Planning and Building Department ZONING INFORMATION Building Height and Cellars, Basements and Crawl Spaces Updated: 2017 August 25 This brochure outlines zoning information for single-family and two-family dwellings in the R1 to R5 and R9 to R12 Districts. For specific information on measuring building height and calculating floor area in R10 District please see the brochure on R10 zoning. This information is provided for convenience only and is not in substitution of applicable City Bylaws or Provincial or Federal Codes or laws. You must satisfy yourself that any existing or proposed construction or other works complies with such Bylaws, Codes or other laws." Other brochures related to this topic Parking Areas and Driveways - for Single and Two Family dwellings R10 District (as it relates to measuring building height and calculating floor area in that zoning district) Legal Survey Requirements for Single and Two Family Dwellings Zoning Bylaw Definitions front average elevation means the average elevation of the natural grade along the exterior of the building facing the front lot line. rear average elevation means the average elevation of the natural grade along the exterior of the building facing the rear lot line or, for a through lot, the other front lot line. natural grade level means, for the purpose of measuring the height of a building or determining a basement or cellar, the ground level adjacent to the exposed wall of a building, with no adjustment having been made to the existing undisturbed ground level except for a minor slope equalization as approved by the Building Inspector. height means the vertical dimension of a building or structure measured in accordance with Section 6.4 of the Zoning Bylaw. storey means a habitable space between two floors, or between any floor and the upper surface of the floor next above, except that the topmost storey shall be that portion of a building included between the upper surface of the topmost floor and the ceiling above. A basement shall be considered as a storey. flat roof means a roof on a building that has one or more roof surfaces that have a pitch of less than 4 in 12 and cover an area greater than 20 percent of the area of all roof surfaces as measured in plan view.
sloping roof means a roof on a building that has one or more roof surfaces that have a pitch of 4 in 12 or greater and cover an area at least equal to 80 percent of the area of all roof surfaces as measured in plan view. cellar means the portion of a building between two floor levels that is partly or wholly underground and has more than one-half its height, from its finished floor to the underside of the joists of the floor next above it, below average natural grade as determined by the Building Inspector. A cellar shall not be considered to be a storey. basement means the portion of a building between two floor levels that is partly underground but has at least one-half of its height, from its finished floor to the underside of the joists of the floor next above it, above average natural grade as determined by the Building Inspector. A basement shall be considered to be a storey. crawl space means the space at or below natural grade between the underside of the joists of the floor next above and the floor slab on the ground surface below, having a vertical clear height less than 1.2 m (3.9 feet). Measuring the Height of the Principal Building Except in the R10 District (see R10 District brochure) the height of a house is measured from the lower of the front average elevation or the rear average elevation to the highest point of the building. The top of the railing, skylights or parapet for roof decks is included in the measurement of height. The following types of structures are not included in the calculation of the building height: aerials, electrical service masts, television and radio antennae, chimneys, flues, flagpoles, vents, transmissions towers and water tanks; but no such structure shall cover more than 20 percent of the lot or, if located on a building, more than 10 percent of the roof area of the building. Determining the front and rear average elevation Calculate the average natural grade across the front and across the rear of the building. In most instances, the grade elevations at the two front building corners and two rear building corners are measured and averaged, respectively. The natural grade level is defined as the existing undisturbed ground level. However, if there are changes to the natural grade, then the building height is measured from the lower of the natural grade level or the finished grade level. On site, any adjustment to the approved grade must be authorized by the Building Inspector who takes into consideration the elevation of adjacent properties, the street and the lane. Building Height & Cellars, 2 Revised: 2017 August 25
Height is measured from the lower of the natural grade level or the finished grade level. existing grade - 108' finished grade - 109' FRONT YARD existing grade - 105' finished grade - 106' REAR YARD existing grade - 105' finished grade - 104' existing grade - 101' finished grade - 100' EXISTING GRADE HEIGHT FRONT AVERAGE ELEVATION : 106' REAR AVERAGE ELEVATION : 102.5' FRONT AVERAGE ELEVATION : 106' FINISHED GRADE REAR AVERAGE ELEVATION : 102.5' Attached garages and carports: The natural grade on the driveway side of a house may be lowered up to a width of 6.7 m (22.0 ft.) without affecting the calculation of the front or rear average elevation for measuring building height and determining cellar slab elevation. If the natural grade on the driveway side of the house is lowered beyond a width of 6.7 m (22.0 ft.) for a driveway, then the front or rear average elevation will be calculated from that lower level. For more information on driveway requirements, please refer to the brochure titled Parking Areas and Driveways - Single and Two Family Dwellings. 2 2 EE TF O R L E S S G R E A T E R T H A N 2 2 f e e t T H E E L E V A T I O N A T T H E S E P O I N T S W I L L B E U S E D T O C A L C R E A R E L E V A T I O N W H E N D E T E R M I N I N G B U I L D I N G H E I G H T H A S A B A S E M E N T O R A C E L L A R. Window wells: To provide light to a cellar or basement, window wells may be constructed without affecting the calculation of average natural grade for determining a cellar or a basement. To be excluded from the calculation of average natural grade, the window wells shall not extend more than 0.9 m (3.0 feet) from the building; Building Height & Cellars, 3 Revised: 2017 August 25
extend more than.75 m (2.5 feet) into the required side yards; and exceed in length 25 percent of the length of the wall. If any of these three conditions are not met, then the window well will be included in the calculation of average natural grade. Access to a cellar or basement: 100% maximum projection of 2.5 ft. into a required side yard WALL LENGTH maximum length: 25% of wall length 25% 0% maximum projection of 3ft. from the building To provide for pedestrian access to a cellar or basement from the outside, the surface of the ground abutting the house may be lowered without affecting the calculation of average natural grade for determining a cellar or basement. To be excluded from the calculation of average natural grade, the lowered surface must not be located on the same side of the building as a lowered driveway to an attached garage/carport; exceed an area of 14.0m 2 (150.7 sq. feet) (including stairs); extend more than 3.0 m (9.8 feet) from the building; exceed an aggregate width of 4.5 m (14.8 feet) along the wall; and extend more than 0.75 m (2.5 feet) into the required side yards. If any of these conditions are not met, then the lowered surface will be included in the calculation of average natural grade. The intent of this regulation is to ensure that the existing grade is not altered significantly. It does not apply to vehicular access to an attached garage or carport. Building Height & Cellars, 4 Revised: 2017 August 25
L A N E DETACHED GARAGE 14.8 ft. LOWERED SURFACE S T R E E T 9.8 ft. IN MOST INSTANCES THE ELEVATION AT THESE POINTS WILL BE USED IN THE CALCULATION OF THE AVERAGE. Additions to older houses Houses with a building permit issued on or before 1991 December 16 To accommodate additions to older houses (particularly those on sloping lots), the height of any addition is measured from the lower of the front average elevation or the rear average elevation to the highest point of the addition (i.e., not the highest point of the existing building). NATURAL GRADE EXISTING HEIGHT ADDITION For houses approved after this date, height is measured from the lower of the front average elevation or rear average elevation to the highest point of the building). Determining Cellars, Basements and Crawl Spaces Cellars A cellar is defined as having more than one-half its height below the average natural grade and is not considered to be a storey. For all houses, it is included in the calculation of gross floor area, but not in the calculations of above grade floor area. The height of a cellar must not be less than 2.3m (7.5 feet), measured between the floor and the ceiling (to the underside of the joists). To locate a cellar on a flat site or a sloping site calculate the average natural grade by averaging the elevations at the front and rear Building Height & Cellars, 5 Revised: 2017 August 25
corners of the building; measure the height of the cellar, from its finished floor to the underside of the joists of the floor above it; locate at least one-half the height of the cellar below the average natural grade. FRONT REAR AVERAGE AT LEAST HALF THE HEIGHT OF THE CELLAR IS LOCATED BELOW THE AVERAGE cellar Basements A basement is defined as being partly underground and having more than one-half its height above the average natural grade. A basement is considered to be a storey. It is included in the calculation of gross floor area for all houses and in the calculation of above grade floor area for houses with a building permit issued after 1991 December 16. The height of a basement must not be less than 2.3 m (7.5 feet, measured between the floor and the ceiling (to the underside of the joists). To locate a basement on a flat or a sloping site calculate the average natural grade by averaging the elevations at the front and rear corners of the building; measure the height of the basement, from its finished floor to the underside of the joists of the floor above it; locate at least one-half the height of the basement above the average natural grade. Building Height & Cellars, 6 Revised: 2017 August 25
FRONT REAR AVERAGE AT LEAST HALF OF THE HEIGHT OF TH E BASEMENT IS ABOVE THE AVERAGE basement Crawl spaces A crawl space is the space at or below natural grade between the underside of the joists of the floor next above and the floor slab on the ground surface below. It is defined as having a vertical clear height less than 1.2 m (3.9 feet). It is not considered to be a storey and is not included in the calculation of gross floor area. crawl space cellar 3.9 ft. or less Foundation wall must not be lower than required for the depth of the crawlspace. 3.9 ft. For Further Information This brochure is intended for convenience only and cannot be used as a substitute for the Burnaby Zoning Bylaw. To obtain additional information, please call the Building Department at 604-294-7130. Q:\Brochures-Bulletins & Zoning Information\Zoning Information\Building Height and Cellars, Basements and Crawl Spaces\Bulding Height and Cellars, Basements and Crawlspaces REV 2017 Aug 25.docx Building Height & Cellars, 7 Revised: 2017 August 25