A 2-STOREY STRUCTURE SITUATED ON AN R-1 THROUGH LOT
(8 Questions, Difficulty Level: MODERATE)
by Raison John J. Bassig
Given the illustrated 2-storey structure situated on an R-1 through lot.
Lot Size: 10m wide x 21m deep
Main RROW Width: 20m
Secondary RROW Width: 12m
Sidewalk Elevation Mark: EL = 0.00m
G/F Line Elevation Mark: EL + 850mm
2/F Line Elevation Mark: EL + 5000mm
Top of Roof Beam Elevation Mark: EL + 8620mm
Roof Apex Elevation Mark: EL + 10530mm
Line of Eaves: 310mm below Top of Roof Beam
Main RROW Width: 20m
Secondary RROW Width: 12m
Sidewalk Elevation Mark: EL = 0.00m
G/F Line Elevation Mark: EL + 850mm
2/F Line Elevation Mark: EL + 5000mm
Top of Roof Beam Elevation Mark: EL + 8620mm
Roof Apex Elevation Mark: EL + 10530mm
Line of Eaves: 310mm below Top of Roof Beam
Answer the following questions considering all applicable provisions of the 2004 Implementing Rules and Regulations (IRR) of the National Building Code of the Philippines (PD1096):
Q#1: What is the Suggested Minimum Width of the Carriageway for the 20-m RROW?
a. 16.00m
b. 16.70m
c. 13.40m
d. 13.00m
e. 14.00m
The answer is straightforward by referring to the table of Suggested Median and Lane Widths Within Alleys/Roadways/Carriageways by Minium RROW Width of the code, which states,
Therefore, the correct answer is c. 13.40m.
"6.10m to 20.00m RROW ==> 13.40m Roadway/Carriageway (for 20.00 meters RROW)"
(Rule VIII, Guidelines on Street/RROWS..., Table VIII.G.2 of the 2004 IRR of PD1096)
(Rule VIII, Guidelines on Street/RROWS..., Table VIII.G.2 of the 2004 IRR of PD1096)
Therefore, the correct answer is c. 13.40m.
Q#2: What is the actual building footprint, considering the structure's perimeter walls are along the AMBF?
a. 72 sqm
b. 87 sqm
c. 90 sqm
d. 96 sqm
e. 147 sqm
The Allowable Maximum Building Footprint (AMBF) can be determined using several provisions in the code. Let's look at these provisions one by one:
First, we refer to the table of Maximum Allowable Percentage of Site Occupancy (PSO) based on the Type of Land Use Zoning of the project.
As we can see, in this particular table, residential occupancies zoned as R-1 is NOT provided. So, we can skip this provision and proceed with the others.
Next, we refer to the table of Minimum Setbacks for Residential Buildings/Structures. It is given in the problem that the lot is zoned as R-1. We can see in the table that the required minimum setbacks are,
It is clear in the Project Data and Illustration that the 10m x 21m lot is a THROUGH LOT, bounded by two streets along its 10m-wide frontage. Since the lot is a through lot, we will consequently have two (2) frontages. This means that at both sides of the building facing an RROW, we must apply the front setbacks required -- NO "rear" setbacks -- because any yards facing an RROW is considered a FRONT yard. So,
Lastly, we refer to the table of Minimum Total Open Space within Lot (TOSL) based on Lot Type. This table prescribes the TOSL, and consequently, the AMBF (since Total Lot Area, TLA = TOSL + PSO or AMBF). Note that R-1 structures are prohibited to have firewalls (see Sec. 704.4.c.iii and Sec. 803.4.c.i). We can see in the table that,
The table tells us that a minimum of 30% of the TLA must be TOSL. Since TLA = PSO + TOSL, then, the AMBF, as far as Table VIII.G.6 is concerned, is prescribed at a maximum of 70% of the TLA. As our TLA is given as 10m x 21m or equal to 210sqm, then,
So, at this point, after considering several provisions of the code, we have two (2) different resulting values for the AMBF,
Since we are looking for the MAXIMUM value (Maximum Footprint) allowed by the code, the LESSER value MUST GOVERN to conform with the code.
Therefore, the correct answer is a. 72 sqm (Based on Min. Setbacks per Table VIII.2).
First, we refer to the table of Maximum Allowable Percentage of Site Occupancy (PSO) based on the Type of Land Use Zoning of the project.
As we can see, in this particular table, residential occupancies zoned as R-1 is NOT provided. So, we can skip this provision and proceed with the others.
Next, we refer to the table of Minimum Setbacks for Residential Buildings/Structures. It is given in the problem that the lot is zoned as R-1. We can see in the table that the required minimum setbacks are,
"R-1 ==> 4.50 meters (Front); 2.00 meters (Side); 2.00 meters (Rear)"
(Rule VIII, Table VIII.2 of the 2004 IRR of PD1096)
(Rule VIII, Table VIII.2 of the 2004 IRR of PD1096)
It is clear in the Project Data and Illustration that the 10m x 21m lot is a THROUGH LOT, bounded by two streets along its 10m-wide frontage. Since the lot is a through lot, we will consequently have two (2) frontages. This means that at both sides of the building facing an RROW, we must apply the front setbacks required -- NO "rear" setbacks -- because any yards facing an RROW is considered a FRONT yard. So,
Max. Bldg. Width = Lot Width - Side Setback (Left) - Side Setback (Right)
Max. Bldg. Width = 10m - 2m - 2m
Max. Bldg. Width = 6m
Max. Bldg. Depth = Lot Depth - Front Setback (facing 20m RROW) - Front Setback (facing 12m RROW)
Max. Bldg. Depth = 21m - 4.5m - 4.5m
Max. Bldg. Depth = 12m
AMBF = Max. Bldg. Width x Max. Bldg. Depth
AMBF = 6m x 12m
AMBF = 72sqm (Based on Min. Setbacks per Table VIII.2)
Max. Bldg. Width = 10m - 2m - 2m
Max. Bldg. Width = 6m
Max. Bldg. Depth = Lot Depth - Front Setback (facing 20m RROW) - Front Setback (facing 12m RROW)
Max. Bldg. Depth = 21m - 4.5m - 4.5m
Max. Bldg. Depth = 12m
AMBF = Max. Bldg. Width x Max. Bldg. Depth
AMBF = 6m x 12m
AMBF = 72sqm (Based on Min. Setbacks per Table VIII.2)
Lastly, we refer to the table of Minimum Total Open Space within Lot (TOSL) based on Lot Type. This table prescribes the TOSL, and consequently, the AMBF (since Total Lot Area, TLA = TOSL + PSO or AMBF). Note that R-1 structures are prohibited to have firewalls (see Sec. 704.4.c.iii and Sec. 803.4.c.i). We can see in the table that,
"Through Lot ==> Without Firewall ==> Group A (Residential) ==> R-1 ==> 30% of the TLA"
(Rule VIII, Table VIII.G.6 of the 2004 IRR of PD1096)
(Rule VIII, Table VIII.G.6 of the 2004 IRR of PD1096)
The table tells us that a minimum of 30% of the TLA must be TOSL. Since TLA = PSO + TOSL, then, the AMBF, as far as Table VIII.G.6 is concerned, is prescribed at a maximum of 70% of the TLA. As our TLA is given as 10m x 21m or equal to 210sqm, then,
AMBF = 70% x TLA
AMBF = 0.70 x 210sqm
AMBF = 147sqm (Based on Min. TOSL per Table VIII.G.6)
AMBF = 0.70 x 210sqm
AMBF = 147sqm (Based on Min. TOSL per Table VIII.G.6)
So, at this point, after considering several provisions of the code, we have two (2) different resulting values for the AMBF,
AMBF = 72sqm (Based on Min. Setbacks per Table VIII.2)
AMBF = 147sqm (Based on Min. TOSL per Table VIII.G.6)
AMBF = 147sqm (Based on Min. TOSL per Table VIII.G.6)
Since we are looking for the MAXIMUM value (Maximum Footprint) allowed by the code, the LESSER value MUST GOVERN to conform with the code.
Therefore, the correct answer is a. 72 sqm (Based on Min. Setbacks per Table VIII.2).
Q#3: Based on the actual floor area, compute the remaining Gross Floor Area (GFA) to reach the Designated FLAR limit.
a. 171 sqm
b. 219 sqm
c. 72 sqm
d. 297 sqm
e. None; limit has been reached
In the Illustration of the Problem, it has been shown that the ACTUAL building footprint will be along the AMBF, so, our actual floor area (per storey) is considered to be 72sqm (equal to the AMBF as solved in Q#2). As the project is a 2-storey residence, and shown in the Illustration that both G/F and 2/F have the same footprint/floorplate, then,
This 144sqm is considered as our Total Gross Floor Area (TGFA) since it encompasses all the floor areas of the structure.
On the other hand, the Gross Floor Area (GFA) specifically excludes certain areas defined in the code as follows,
Since in the given problem, there is NO mention of any specific rooms or spaces in the structure, we can refer to the Conversion Table of Gross Floor Area (GFA) to Total Gross Floor Area (TGFA) in the code where it states,
The table means that ~33% of the TGFA are non-GFA areas, therefore, ~67% of the TGFA are GFA areas. It is also prescribed in the table, using a multiplier, that TGFA = [GFA x 1.50], or, GFA = [TGFA / 1.50]. Since we have already determined that our TGFA (our Actual Floor Area) is 144sqm, then, we calculate the GFA as,
The GFA or Gross Floor Area (NOT the TGFA) is used when computing for the Floor-to-Lot Area Ratio (FLAR). Typically, city/municipality zoning ordinances sets FLAR limits to control the density of their respective localities. Since the problem did not mention any specific location or any ordinances, we will use the maximum FLAR based on the type of use or occupancy of a project as prescribed in the National Building Code. We refer to the Reference Table of Floor to Lot Area Ratio (FLAR) Designations/Rights, where it states,
The table means that a MAXIMUM of 1.50 Floor-to-Lot Area Ratio may be permitted for R-1 structures (at a 3-storey or 10.00m Building Height Limit). Recall the formula for FLAR,
Since the maximum FLAR for our project is given at [1.50], and our Total Lot Area (TLA) is 10m x 21m = [210sqm], then, we can compute the maximum allowable GFA as,
As our GFA (converted from the TGFA) was calculated at only 96sqm, then, the remaining GFA allowed by the code that we can still use if we want to maximize the development potential of the lot would be,
Therefore, the correct answer is b. 219 sqm.
Actual Total Floor Area = 72sqm x 2 storeys
Actual Total Floor Area = 144sqm
Actual Total Floor Area = 144sqm
This 144sqm is considered as our Total Gross Floor Area (TGFA) since it encompasses all the floor areas of the structure.
On the other hand, the Gross Floor Area (GFA) specifically excludes certain areas defined in the code as follows,
"GROSS FLOOR AREA (GFA) - the total floor space within the perimeter of the permanent external building walls (inclusive of main and auxiliary buildings) such as office areas, residential areas, corridors, lobbies and mezzanine level/s. The GFA shall also include building projections which may serve as floors or platforms that are directly connected to/integrated with areas within the building/structure, e.g. balconies and the GFA EXCLUDES the following:
(a) Covered areas used for parking and driveways, services and utilities;
(b) Vertical penetrations in parking floors where no residential or office units are present;
(c) Uncovered areas for helipads, air-conditioning cooling towers or air-conditioning condensing unit (ACCU) balconies, overhead water tanks, roof decks, laundry areas and cages, wading or swimming pools, whirlpools or jacuzzis, terraces, gardens, courts or plazas, balconies exceeding 10.00 sq. meters, fire escape structures and the like."
(a) Covered areas used for parking and driveways, services and utilities;
(b) Vertical penetrations in parking floors where no residential or office units are present;
(c) Uncovered areas for helipads, air-conditioning cooling towers or air-conditioning condensing unit (ACCU) balconies, overhead water tanks, roof decks, laundry areas and cages, wading or swimming pools, whirlpools or jacuzzis, terraces, gardens, courts or plazas, balconies exceeding 10.00 sq. meters, fire escape structures and the like."
Since in the given problem, there is NO mention of any specific rooms or spaces in the structure, we can refer to the Conversion Table of Gross Floor Area (GFA) to Total Gross Floor Area (TGFA) in the code where it states,
"Residential 1 ==> 33% of TGFA (Excluded Floor Areas/non-GFA) ==> 1.50 Multiplier to Convert GFA to TGFA"
(Rule VII, Guidelines on Building Bulk and Development Controls..., Table VII.G.2 of the 2004 IRR of PD1096)
(Rule VII, Guidelines on Building Bulk and Development Controls..., Table VII.G.2 of the 2004 IRR of PD1096)
The table means that ~33% of the TGFA are non-GFA areas, therefore, ~67% of the TGFA are GFA areas. It is also prescribed in the table, using a multiplier, that TGFA = [GFA x 1.50], or, GFA = [TGFA / 1.50]. Since we have already determined that our TGFA (our Actual Floor Area) is 144sqm, then, we calculate the GFA as,
GFA (for R-1 Occupancy) = TGFA / 1.50
GFA (for R-1 Occupancy) = 144sqm / 1.50
GFA (for R-1 Occupancy) = 96sqm
GFA (for R-1 Occupancy) = 144sqm / 1.50
GFA (for R-1 Occupancy) = 96sqm
The GFA or Gross Floor Area (NOT the TGFA) is used when computing for the Floor-to-Lot Area Ratio (FLAR). Typically, city/municipality zoning ordinances sets FLAR limits to control the density of their respective localities. Since the problem did not mention any specific location or any ordinances, we will use the maximum FLAR based on the type of use or occupancy of a project as prescribed in the National Building Code. We refer to the Reference Table of Floor to Lot Area Ratio (FLAR) Designations/Rights, where it states,
"Residential ==> Residential 1 (R-1) ==> 1.50 (at a 3-storey or 10.00m BHL)"
(Rule VII, Guidelines on Building Bulk and Development Controls..., Table VII.G.1 of the 2004 IRR of PD1096)
(Rule VII, Guidelines on Building Bulk and Development Controls..., Table VII.G.1 of the 2004 IRR of PD1096)
The table means that a MAXIMUM of 1.50 Floor-to-Lot Area Ratio may be permitted for R-1 structures (at a 3-storey or 10.00m Building Height Limit). Recall the formula for FLAR,
FLAR = GFA / TLA
Since the maximum FLAR for our project is given at [1.50], and our Total Lot Area (TLA) is 10m x 21m = [210sqm], then, we can compute the maximum allowable GFA as,
Maximum Allowable GFA = [Maximum FLAR Rights] x [TLA]
Maximum Allowable GFA = [1.50] x [210sqm]
Maximum Allowable GFA = 315sqm
Maximum Allowable GFA = [1.50] x [210sqm]
Maximum Allowable GFA = 315sqm
As our GFA (converted from the TGFA) was calculated at only 96sqm, then, the remaining GFA allowed by the code that we can still use if we want to maximize the development potential of the lot would be,
Remaining GFA to reach Max. FLAR = Maximum Allowable GFA - Actual GFA
Remaining GFA to reach Max. FLAR = 315sqm - 96sqm
Remaining GFA to reach Max. FLAR = 219sqm
Remaining GFA to reach Max. FLAR = 315sqm - 96sqm
Remaining GFA to reach Max. FLAR = 219sqm
Therefore, the correct answer is b. 219 sqm.
Q#4: Determine the actual Building Height of the structure based on the given elevation marks.
a. 9.11m
b. 9.42m
c. 9.575m
d. 10.22m
e. 10.53m
The height of a building is GENERALLY measured from the established grade line to the topmost portion of the proposed building/structure. The "established grade line" is usually the highest adjoining natural grade (ground surface) OR finished grade (sidewalk surface) based on the code (see Sec. 707.2, Notes of the 2004 IRR of PD1096).
Emphasis on "GENERALLY" as the height is NOT ALWAYS measured up to the topmost portion of the building. Exceptions such as signages, masts, antennae, beacons and the like are EXCLUDED (see Sec. 707.2.a of the 2004 IRR of PD1096). Moreover, the height of buildings with flat roofs are measured from established grade up to its flat level roofing OR its parapet wall, if any; while the height of buildings with pitched, gabled, or hipped roof are measured from established grade up to the midpoint of such type of roof only.
Based on the Illustration of the problem, we can clearly see that the structure has a hip roof. This means that the roof apex, marked as EL + 10530mm (or 10.53m from the sidewalk level) is NOT the building height. As provided for by the code in the above figures, the height is measured up to the midpoint (vertical half) of the sloped roof only.
Since the roof apex is 10.53m from the sidewalk (the established grade), and the roof eaves is 0.31m below the top of roof beams (where the top of roof beams is 8.62m from the sidewalk), we can get the vertical distance of the sloped roof as,
So,
So, the building height can now be computed as,
Therefore, the correct answer is b. 9.42m.
Emphasis on "GENERALLY" as the height is NOT ALWAYS measured up to the topmost portion of the building. Exceptions such as signages, masts, antennae, beacons and the like are EXCLUDED (see Sec. 707.2.a of the 2004 IRR of PD1096). Moreover, the height of buildings with flat roofs are measured from established grade up to its flat level roofing OR its parapet wall, if any; while the height of buildings with pitched, gabled, or hipped roof are measured from established grade up to the midpoint of such type of roof only.
(Figure VII.1, Figure VII.2, and Figure VII.3 of the 2004 IRR of PD1096)
Based on the Illustration of the problem, we can clearly see that the structure has a hip roof. This means that the roof apex, marked as EL + 10530mm (or 10.53m from the sidewalk level) is NOT the building height. As provided for by the code in the above figures, the height is measured up to the midpoint (vertical half) of the sloped roof only.
Since the roof apex is 10.53m from the sidewalk (the established grade), and the roof eaves is 0.31m below the top of roof beams (where the top of roof beams is 8.62m from the sidewalk), we can get the vertical distance of the sloped roof as,
Vertical Roof Distance = Roof Apex - (Top of Roof Beam Elev. - Roof Eave Dist. from Top of Roof Beam)
Vertical Roof Distance = 10.53m - (8.62m - 0.31m)
Vertical Roof Distance = 2.22m (from Roof Eaves to Roof Apex)
Vertical Roof Distance = 10.53m - (8.62m - 0.31m)
Vertical Roof Distance = 2.22m (from Roof Eaves to Roof Apex)
So,
Midpoint of Roof Height = 2.22m / 2 = 1.11m (measured from Roof Eaves)
So, the building height can now be computed as,
Building Ht. = [Top of Roof Beam Elev. - Roof Eave Dist. from Top of Roof Beam] + Midpoint of Roof Height
Building Ht. = [8.62m - 0.31m] + 1.11m
Building Ht. = 9.42m
Building Ht. = [8.62m - 0.31m] + 1.11m
Building Ht. = 9.42m
Therefore, the correct answer is b. 9.42m.
Q#5: Considering that all roof eaves are at its maximum length allowed by the code, what would be the projection of the eaves fronting the 12-m RROW?
a. 1.50m
b. 1.20m
c. 1.588m
d. 0.5m
e. 2m
Eaves are considered projections from the Outermost Face of the Building (OFB). Determining the Outermost Limits of Building Projection (OLBP) for the eaves can be done by referring to several pertinent provisions in the code. Let's look at each one:
One method is using the Angular Plane, a slope measured from the centerline of a given RROW to find the building limits (OFB or OLBP). An example is given in the code,
To find out the corresponding angle to use for our R-1 structure with building projections (eaves) along the 12-m RROW, we refer to the table of Angles/Slopes To Satisfy Natural Light and Ventilation Requirements Along RROW and Front Yards where we can see that,
The table tells us that at the centerline of the 12m-wide RROW, the Angular Plane which sets the limits of our building lines is given at 43° from the horizontal. The height of the roof eaves can be determined based on the given elevation marks/data shown in the Illustration of the Problem,
We need to find out the maximum horizontal projection of the eaves along this 8.31m elevation measured from the OFB (which is the line of the AMBF determined in Q#2 to be 4.5m front setback) up to a point along the 43° Angular Plane limit.
This can be solved using simple trigonometric functions,
Another method is based on the definition of the Outermost Limits of Building Projections, where the code states,
Since our prescribed setback along the 12m-wide RROW is 4.5m, then, the maximum horizontal projection of the eaves would be,
Lastly, we can also check several illustrations in the code that prescribes the Maximum Building Projection as 1/3 of the Front Setback, as shown in these figures,
Since our front setback along the 12m-wide RROW is 4.5m, then, the maximum horizontal projection of the eaves would be,
At this point, after using several methods in determining the Maximum Building Projections, we have three (3) different values for our Eave Projection,
Since we are looking for the MAXIMUM value, then, the LEAST value among the three must GOVERN (1.50m) as our maximum eave projection along the 12m-wide RROW.
Therefore, the correct answer is a. 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2).
One method is using the Angular Plane, a slope measured from the centerline of a given RROW to find the building limits (OFB or OLBP). An example is given in the code,
(Figure VII.G.1 of the 2004 IRR of PD1096)
To find out the corresponding angle to use for our R-1 structure with building projections (eaves) along the 12-m RROW, we refer to the table of Angles/Slopes To Satisfy Natural Light and Ventilation Requirements Along RROW and Front Yards where we can see that,
"Residential 1 (R-1) ==> 12.00 meters RROW Width ==> Angle for Buildings With Projections ==> 43° (from Centerline of RROW)"
(Rule VII, Table VII.G.3 of the 2004 IRR of PD1096)
(Rule VII, Table VII.G.3 of the 2004 IRR of PD1096)
The table tells us that at the centerline of the 12m-wide RROW, the Angular Plane which sets the limits of our building lines is given at 43° from the horizontal. The height of the roof eaves can be determined based on the given elevation marks/data shown in the Illustration of the Problem,
Height of Roof Eave Line = Top of Roof Beam Elevation Mark - Distance of Roof Eave from Top of Roof Beam
Height of Roof Eave Line = 8.62m - 0.31m
Height of Roof Eave Line = 8.31m
Height of Roof Eave Line = 8.62m - 0.31m
Height of Roof Eave Line = 8.31m
We need to find out the maximum horizontal projection of the eaves along this 8.31m elevation measured from the OFB (which is the line of the AMBF determined in Q#2 to be 4.5m front setback) up to a point along the 43° Angular Plane limit.
This can be solved using simple trigonometric functions,
Max. Eave Projection = [Dist. from Centerline of RROW to OFB] - [Dist. from Centerline of RROW to Eave]
Max. Eave Projection = [Front Setback + Half of 12-m RROW] - [Height of Eaves / Tan43°]
Max. Eave Projection = [4.5m + 6m] - [8.31m / Tan43°]
Max. Eave Projection = [10.5m] - [~8.91138m]
Max. Eave Projection = ~1.588m (Based on Slope of Angular Plane in Table VII.G.3 and Figure VII.G.1)
Max. Eave Projection = [Front Setback + Half of 12-m RROW] - [Height of Eaves / Tan43°]
Max. Eave Projection = [4.5m + 6m] - [8.31m / Tan43°]
Max. Eave Projection = [10.5m] - [~8.91138m]
Max. Eave Projection = ~1.588m (Based on Slope of Angular Plane in Table VII.G.3 and Figure VII.G.1)
Another method is based on the definition of the Outermost Limits of Building Projections, where the code states,
"OUTERMOST LIMITS OF BUILDING PROJECTIONS (OLBP) - The outermost horizontal limit of projections, i.e., canopies, porte cocheres, balconies, eaves, roofs, decks, terraces and the like) from a proposed building/structure above the first floor. The horizontal projections must NOT EXCEED 60% of the PRESCRIBED SETBACK for a GIVEN PROPERTY LINE...xxx..."
(Glossary of the 2004 IRR of PD10096)
(Glossary of the 2004 IRR of PD10096)
Since our prescribed setback along the 12m-wide RROW is 4.5m, then, the maximum horizontal projection of the eaves would be,
Max. Eave Projection = 60% of Prescribed Setback
Max. Eave Projection = 0.6 x 4.5m
Max. Eave Projection = 2.7m (Based on Definition of OLBP in the Glossary)
Max. Eave Projection = 0.6 x 4.5m
Max. Eave Projection = 2.7m (Based on Definition of OLBP in the Glossary)
Lastly, we can also check several illustrations in the code that prescribes the Maximum Building Projection as 1/3 of the Front Setback, as shown in these figures,
(Figures VIII.G.11, VIII.G.12, XX.1, XX.2 of the 2004 IRR of PD1096)
Since our front setback along the 12m-wide RROW is 4.5m, then, the maximum horizontal projection of the eaves would be,
Max. Eave Projection = 1/3 of Front Setback
Max. Eave Projection = (1/3) x 4.5m
Max. Eave Projection = 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2)
Max. Eave Projection = (1/3) x 4.5m
Max. Eave Projection = 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2)
At this point, after using several methods in determining the Maximum Building Projections, we have three (3) different values for our Eave Projection,
Max. Eave Projection = ~1.588m (Based on Slope of Angular Plane in Table VII.G.3 and Figure VII.G.1)
Max. Eave Projection = 2.7m (Based on Definition of OLBP in the Glossary)
Max. Eave Projection = 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2)
Max. Eave Projection = 2.7m (Based on Definition of OLBP in the Glossary)
Max. Eave Projection = 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2)
Since we are looking for the MAXIMUM value, then, the LEAST value among the three must GOVERN (1.50m) as our maximum eave projection along the 12m-wide RROW.
Therefore, the correct answer is a. 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2).
Q#6: What is the eave length at one of the lot's side?
a. 1.25m
b. 1.35m
c. 1.2m
d. 750mm
e. Same as the eave length along the 12m-wide RROW front yard
Eaves are considered projections from the Outermost Face of the Building (OFB). Determining the Outermost Limits of Building Projection (OLBP) for the eaves, particularly at the SIDE YARD, is governed by several pertinent provisions in the code. Let's look at these:
First, we refer to the definition of Outermost Limits of Building Projections, where the code states,
Since our prescribed setback along the side yard was determined in Q#2 to be 2m, then, the maximum horizontal projection of the eaves would be,
Secondly, we refer to a couple of provisions in the code pertaining to eaves located along the sides and rear yards,
Since the above provisions requires a MINIMUM of 0.75m distance measured from the outermost projection of the eaves to the side and/or rear property lines, then, given a 2m side setback, our maximum eave projection would be,
So, at this point, we have two (2) different values of the Max. Eave Projection along the side yards,
Since we are looking for the MAXIMUM value, then, the LESSER value must GOVERN (1.2m) as our maximum eave projection along the side yards.
Therefore, the correct answer is c. 1.2m (Based on Definition of OLBP in the Glossary).
First, we refer to the definition of Outermost Limits of Building Projections, where the code states,
"OUTERMOST LIMITS OF BUILDING PROJECTIONS (OLBP) - The outermost horizontal limit of projections, i.e., canopies, porte cocheres, balconies, eaves, roofs, decks, terraces and the like) from a proposed building/structure above the first floor. The horizontal projections must NOT EXCEED 60% of the PRESCRIBED SETBACK for a GIVEN PROPERTY LINE...xxx..."
(Glossary of the 2004 IRR of PD10096)
(Glossary of the 2004 IRR of PD10096)
Since our prescribed setback along the side yard was determined in Q#2 to be 2m, then, the maximum horizontal projection of the eaves would be,
Max. Eave Projection = 60% of Prescribed Setback
Max. Eave Projection = 0.6 x 2m
Max. Eave Projection = 1.2m (Based on Definition of OLBP in the Glossary)
Max. Eave Projection = 0.6 x 2m
Max. Eave Projection = 1.2m (Based on Definition of OLBP in the Glossary)
Secondly, we refer to a couple of provisions in the code pertaining to eaves located along the sides and rear yards,
"Eaves over required windows shall NOT be less than 750 MILLIMETERS from the SIDE and REAR property lines."
(Sec. 704.1.c of the 2004 IRR of PD1096)
(Sec. 704.1.c of the 2004 IRR of PD1096)
"Eaves, canopies, awnings (or media aguas) over required windows shall NOT be less than 750 MILLIMETERS from the SIDE and REAR property lines."
(Sec. 808.3 of the 2004 IRR of PD1096)
(Sec. 808.3 of the 2004 IRR of PD1096)
Since the above provisions requires a MINIMUM of 0.75m distance measured from the outermost projection of the eaves to the side and/or rear property lines, then, given a 2m side setback, our maximum eave projection would be,
Max. Eave Projection = Prescribed Side/Rear Setback - 0.75m clear distance from Side/Rear Property Line
Max. Eave Projection = 2m - 0.75m
Max. Eave Projection = 1.25m (Based on Sec. 704.1.c and Sec. 808.3)
Max. Eave Projection = 2m - 0.75m
Max. Eave Projection = 1.25m (Based on Sec. 704.1.c and Sec. 808.3)
So, at this point, we have two (2) different values of the Max. Eave Projection along the side yards,
Max. Eave Projection = 1.2m (Based on Definition of OLBP in the Glossary)
Max. Eave Projection = 1.25m (Based on Sec. 704.1.c and Sec. 808.3)
Max. Eave Projection = 1.25m (Based on Sec. 704.1.c and Sec. 808.3)
Since we are looking for the MAXIMUM value, then, the LESSER value must GOVERN (1.2m) as our maximum eave projection along the side yards.
Therefore, the correct answer is c. 1.2m (Based on Definition of OLBP in the Glossary).
Q#7: Given all eaves at max. lengths, what is the horizontal projected roof area?
a. 135.75 sqm
b. 123.48 sqm
c. 124.7 sqm
d. 125.55 sqm
e. 134.9 sqm
As we have already determined the maximum projections of the eaves along the 12m-RROW (solved in Q#5 as 1.50m) and along both side yards (solved in Q#6 as 1.20m each side), we are only left with the unknown eave projection along the 20m-RROW to be able to calculate the entire horizontal projected roof area.
Similar to the procedure we did in Q#5, we first look at the Angular Plane, a slope measured from the centerline of a given RROW to find the building limits (OFB or OLBP). The corresponding angle to use for our R-1 structure with building projections (eaves) along the 20-m RROW is given in the table of Angles/Slopes To Satisfy Natural Light and Ventilation Requirements Along RROW and Front Yards as,
The table tells us that at the centerline of the 20m-wide RROW, the Angular Plane which sets the limits of our building is given at 32° from the horizontal. We have already determined the height of our roof eaves in Q#5 as 8.31m. So, we need to find out the maximum horizontal projection of the eaves along this 8.31m elevation measured from the OFB (which was determined in Q#2 to be 4.5m front setback) up to a point along the 32° angular plane limit.
This can be solved using simple trigonometric functions,
Next, we use the definition of the Outermost Limits of Building Projections (as we also did in Q#5),
Lastly, we use several illustrations in the code as basis of the Maximum Building Projection, prescribed as 1/3 of the Front Setback (as we also did in Q#5),
At this point, after using several methods in determining the Maximum Building Projections, we have three (3) different values for our Eave Projection,
Since we are looking for the MAXIMUM value, then, the LEAST value among the three must GOVERN (1.20m) as our maximum eave projection along the 20m-wide RROW.
Consolidating all known values for all of our eave projections, we have:
The horizontal projected roof area can now be calculated by considering the building floorplate or OFB previously determined in Q#2 (where AMBF = 6m x 12m) and adding the above roof eave lengths projecting from such OFB,
Therefore, the correct answer is b. 123.48 sqm.
Similar to the procedure we did in Q#5, we first look at the Angular Plane, a slope measured from the centerline of a given RROW to find the building limits (OFB or OLBP). The corresponding angle to use for our R-1 structure with building projections (eaves) along the 20-m RROW is given in the table of Angles/Slopes To Satisfy Natural Light and Ventilation Requirements Along RROW and Front Yards as,
"Residential 1 (R-1) ==> 20.00 meters RROW Width ==> Angle for Buildings With Projections ==> 32° (from Centerline of RROW)"
(Rule VII, Table VII.G.3 of the 2004 IRR of PD1096)
(Rule VII, Table VII.G.3 of the 2004 IRR of PD1096)
The table tells us that at the centerline of the 20m-wide RROW, the Angular Plane which sets the limits of our building is given at 32° from the horizontal. We have already determined the height of our roof eaves in Q#5 as 8.31m. So, we need to find out the maximum horizontal projection of the eaves along this 8.31m elevation measured from the OFB (which was determined in Q#2 to be 4.5m front setback) up to a point along the 32° angular plane limit.
This can be solved using simple trigonometric functions,
Max. Eave Projection = [Dist. from Centerline of RROW to OFB] - [Dist. from Centerline of RROW to Eave]
Max. Eave Projection = [Front Setback + Half of 20-m RROW] - [Height of Eaves / Tan32°]
Max. Eave Projection = [4.5m + 10m] - [8.31m / Tan32°]
Max. Eave Projection = [14.5m] - [~13.29878m]
Max. Eave Projection = ~1.20m (Based on Slope of Angular Plane in Table VII.G.3 and Figure VII.G.1)
Max. Eave Projection = [Front Setback + Half of 20-m RROW] - [Height of Eaves / Tan32°]
Max. Eave Projection = [4.5m + 10m] - [8.31m / Tan32°]
Max. Eave Projection = [14.5m] - [~13.29878m]
Max. Eave Projection = ~1.20m (Based on Slope of Angular Plane in Table VII.G.3 and Figure VII.G.1)
Next, we use the definition of the Outermost Limits of Building Projections (as we also did in Q#5),
Max. Eave Projection = 60% of Prescribed Setback
Max. Eave Projection = 0.6 x 4.5m
Max. Eave Projection = 2.7m (Based on Definition of OLBP in the Glossary)
Max. Eave Projection = 0.6 x 4.5m
Max. Eave Projection = 2.7m (Based on Definition of OLBP in the Glossary)
Lastly, we use several illustrations in the code as basis of the Maximum Building Projection, prescribed as 1/3 of the Front Setback (as we also did in Q#5),
Max. Eave Projection = 1/3 of Front Setback
Max. Eave Projection = (1/3) x 4.5m
Max. Eave Projection = 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2)
Max. Eave Projection = (1/3) x 4.5m
Max. Eave Projection = 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2)
At this point, after using several methods in determining the Maximum Building Projections, we have three (3) different values for our Eave Projection,
Max. Eave Projection = ~1.20m (Based on Slope of Angular Plane in Table VII.G.3 and Figure VII.G.1)
Max. Eave Projection = 2.7m (Based on Definition of OLBP in the Glossary)
Max. Eave Projection = 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2)
Max. Eave Projection = 2.7m (Based on Definition of OLBP in the Glossary)
Max. Eave Projection = 1.50m (Based on Max. Bldg. Projections in Figures VIII.G.11, VIII.G.12, XX.1, XX.2)
Since we are looking for the MAXIMUM value, then, the LEAST value among the three must GOVERN (1.20m) as our maximum eave projection along the 20m-wide RROW.
Consolidating all known values for all of our eave projections, we have:
Eaves along 20m-RROW Front Yard = 1.2m (solved above)
Eaves along 12m-RROW Front Yard = 1.5m (from Q#5)
Eaves along Left Side Yard = 1.2m (from Q#6)
Eaves along Right Side Yard = 1.2m (from Q#6)
Eaves along 12m-RROW Front Yard = 1.5m (from Q#5)
Eaves along Left Side Yard = 1.2m (from Q#6)
Eaves along Right Side Yard = 1.2m (from Q#6)
The horizontal projected roof area can now be calculated by considering the building floorplate or OFB previously determined in Q#2 (where AMBF = 6m x 12m) and adding the above roof eave lengths projecting from such OFB,
Horizontal Projected Roof Width = Bldg. Width + Left Side Eave + Right Side Eave
Horizontal Projected Roof Width = 6m + 1.2m + 1.2m
Horizontal Projected Roof Width = 8.4m
Horizontal Projected Roof Depth = Bldg. Depth + Front 12m-RROW Eave + Front 20m-RROW Eave
Horizontal Projected Roof Depth = 12m + 1.5m + 1.2m
Horizontal Projected Roof Depth = 14.7m
Horizontal Projected Roof Area = 8.4m x 14.7m
Horizontal Projected Roof Area = 123.48sqm
Horizontal Projected Roof Width = 6m + 1.2m + 1.2m
Horizontal Projected Roof Width = 8.4m
Horizontal Projected Roof Depth = Bldg. Depth + Front 12m-RROW Eave + Front 20m-RROW Eave
Horizontal Projected Roof Depth = 12m + 1.5m + 1.2m
Horizontal Projected Roof Depth = 14.7m
Horizontal Projected Roof Area = 8.4m x 14.7m
Horizontal Projected Roof Area = 123.48sqm
Therefore, the correct answer is b. 123.48 sqm.
Q#8: If your specification for the eave soffit finish is to use 4mm thk x 1205mm x 2405mm Fiber Cement Boards, how many pieces would you exactly need to cover all eave surface areas?
a. 23 pcs
b. 17 pcs
c. 19 pcs
d. 18 pcs
e. 24 pcs
As we have already calculated in Q#7, the eave surface area can be determined by simply subtracting the building floorplate/OFB from the horizontal projected roof area.
Then, computing the quantity,
Therefore, the correct answer is d. 18 pcs.
Eave Surface Area = Horizontal Projected Roof Area - Building Floorplate/OFB
Eave Surface Area = 123.48 - (6m x 12m)
Eave Surface Area = 51.48sqm
Eave Surface Area = 123.48 - (6m x 12m)
Eave Surface Area = 51.48sqm
Then, computing the quantity,
Quantity of Material = Eave Surface Area / Area of Fiber Cement Board
Quantity of Material = 51.48sqm / (1.205m x 2.405m)
Quantity of Material = 17.7638...pcs or 18 pcs
Quantity of Material = 51.48sqm / (1.205m x 2.405m)
Quantity of Material = 17.7638...pcs or 18 pcs
Therefore, the correct answer is d. 18 pcs.
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