RM3 (By-law 150-85) zone, Cambridge: Multiple Residential RM3

What the RM3 zone permits

• Residential special care facility (max 10 residents; s.3.1.1.3)
• Attached one-family dwellings - linear row houses
• Attached one-family dwellings - cluster row houses
• Detached duplex dwelling
• Semi-detached duplex dwellings (fourplexes)
• Attached duplex dwellings (linear)
• Attached duplex dwellings (cluster)
• Detached triplex dwelling
• Maisonettes
• Mixed terrace
• Apartment house containing 4 or more dwelling units
• Uses permitted in all zones under s.2.1.1
• Accessory uses, buildings and structures (s.2.1.11)
• Home occupation (s.2.1.17)

Standards

Other provisions in this section

• Apartment houses (s.3.1.2.4, by-law p.96, PDF p.114): unit floor area - bachelor per Building Code, 1-bedroom 50 m2, 2+ bedrooms 60 m2; amenity area 20 m2 per bachelor/1-bedroom unit and 30 m2 per unit with 2+ bedrooms; planting strips and fencing per s.2.4.
• Linear development other than apartments (s.3.1.2.5, by-law p.97-99, PDF p.115-117): detached one-family dwelling - frontage 9 m (corner 15 m), lot area 270 m2 (corner 450 m2), front 6 m, rear 7.5 m, interior side 1.2 m, exterior side 6 m, min floor area 75 m2; row houses (RM3 and RM4 only) - 5.5 m and 165 m2 per unit, front 6 m, rear 7.5 m, interior side 1.5 m (3 m where it abuts an R- or RS-class zone), exterior side 6 m, 70 m2 per unit, max 6 attached units (s.4.2.56 lists exempt sites); detached duplex - 15 m, 450 m2, front 6 m, rear 7.5 m, interior side 1.5 m, exterior side 6 m, 70 m2 per unit; semi-detached duplex (fourplex) - 10 m per duplex, 150 m2 per unit, front 6 m, rear 7.5 m, interior side 1.5 m, exterior side 6 m, 70 m2 per unit; attached duplexes - 10 m per duplex, 150 m2 per unit, front 6 m, rear 7.5 m, interior side 3 m, exterior side 6 m, 70 m2 per unit; detached triplex - 15 m, 550 m2, front 6 m, rear 7.5 m, interior side 1.5 m, exterior side 6 m, 70 m2 per unit; maisonette - 30 m, 165 m2 per unit, front 6 m, rear 3 m, interior side 3 m, exterior side 6 m, 60 m2 per unit, 30 m2 private amenity area per unit; mixed terrace - 30 m, 165 m2 per unit, front 6 m, rear 3 m, interior side 3 m, exterior side 6 m, units min 40 m2 (bachelor) / 50 m2 (1-bedroom) / 60 m2 (2+ bedrooms). All linear forms: max lot coverage 40%, min landscaped open space 30%, planting strips and fencing per s.2.4.
• Cluster development (other than apartments) (s.3.1.2.6, by-law p.99-100, PDF p.117-118), RM3 & RM4 column: min lot frontage 20 m; max density 40 units per net residential hectare; front and exterior side yards 6 m; interior side and rear yards 7.5 m, reducible to 3.0 m where a unit wall faces a zone other than an R- or RS-class zone; max lot coverage 40%; unit floor area: bachelor per Building Code, 1-bedroom 50 m2, 2+ bedrooms 60 m2; row houses need 40 m2 private amenity area per unit beside the rear or side wall (reducible to 30 m2 if common amenity area of 3 m2 per unit, min 75 m2 total, is provided); other multiple buildings 30 m2 common amenity area per unit; max 6 attached one-family units in a row (s.4.2.56 exemptions); min landscaped open space 30%; distance between buildings on one lot: 3 m side-to-side, 10 m front-to-rear / front-to-front / rear-to-rear, 8 m front or rear to side.
• More than one residential building may be on an RM lot if all are held in single ownership, a condominium or a housing co-operative (s.3.1.1.1(c), PDF p.105; s.2.1.13.1, PDF p.71).
• Planting strips and fencing (s.2.4, by-law p.81-82, PDF p.99-100) where row houses, attached duplexes, maisonettes, mixed terraces or apartments adjoin an R- or RS-class zone: along rear and interior side lot lines, either a 3 m planting strip with a 1.5 m visual screen (plants or berm) and a 1.5 m chain-link or wrought-iron fence, or a 1.5 m sodded/planting strip with a 1.5 m solid fence; fences within 3 m of a street line max 0.9 m.
• No access driveway, aisle, parking stall or parking lot in an RM-class zone within 6 m of a window of a habitable room whose floor is less than 1.0 m above finished grade (s.2.2.2.3(f), by-law p.72, PDF p.90).
• Children's play areas for apartments, where provided, must be landscaped, have at least three listed pieces of play equipment, and be located to be visible from as many units as possible (s.3.1.1.6, PDF p.107).
• Parking structures less than one storey high or fully below grade may be attached to the principal building; at least 3 m from front and exterior side lot lines and 1.2 m from interior side and rear lot lines (s.2.2.3.8, PDF p.93).
• Apartments with 25 or more units need one 3 m x 10 m loading space (s.2.3.1.2, PDF p.97).
• Paving: parking and driveways in any yard of an apartment house must be asphalt, concrete or another durable all-weather surface (s.2.2.2.4, PDF p.90).
• Compound zones: where an RM zone is combined with N2 or N3 (e.g. N2RM1, N3RM3), RM residential uses are allowed only together with a nursing home or domiciliary hostel on the same site (s.2.1.3.5, PDF p.63).
• In an RM zone these rules apply only on a lot whose principal dwelling is a single detached, semi-detached or street townhouse dwelling; By-law 23-077 does not add units to apartments or other multiple dwellings. 26-007 s.4.19 applies only to land zoned under 26-007. Additional residential units (ARUs), added to 150-85 by By-law 23-077 (enacted 12 September 2023; text from the Council agenda copy, eSCRIBE DocumentId 8407), which repealed By-laws 22-017 and 108-18 and applies to all residentially zoned land: a maximum of two ARUs per lot with a principal dwelling (single detached, semi-detached or street townhouse): two attached, or one attached and one detached (s.3.1.1.11 paras. 3-4). Not permitted with a group home or a boarding, lodging or rooming house (s.3.1.1.11 para. 5), on hazard lands (s.3.1.1.11 para. 8), or on a lot with a bed-and-breakfast hostel (s.2.1.20.8). Parking: one additional space per ARU, which may be tandem and may sit between the building line and the street line; no new driveway or access may be created for an ARU (s.3.1.1.11 para. 6). Where municipal services are available, the principal dwelling and its ARUs must all be connected to municipal water and sewer of adequate size; where they are not, private water and sewer must be shown, to the City's satisfaction, to be capable of serving them all (s.3.1.1.11 para. 7). The ARU entrance may be at most 45 m from the street or highway (s.3.1.1.11 para. 9). Attached ARU: where access is from the interior side yard, the entrance at least 1.2 m from the interior side lot line; where the entrance is a side- or rear-yard door, an unobstructed path at least 0.9 m wide and 2.1 m high from that door to the street; notwithstanding s.2.1.15, only steps or landings up to 1.1 m deep and 0.6 m high may project into the path, and they must keep access to the rear yard and positive drainage on the lot (s.3.1.1.11.1). Detached ARU: in the interior side, exterior side or rear yard; at least 1.2 m from the interior side lot line and the rear lot line (on a through lot accessed by a laneway, 3.0 m from the lot line along the laneway); exterior side yard as for the zone; at least 3 m from the principal dwelling; maximum height 4.5 m; maximum lot coverage 10%; an unobstructed path at least 0.9 m wide and 2.1 m high from the street to its entrance (s.3.1.1.11.2). A detached ARU also counts toward the 10% lot-area cap on accessory buildings (s.2.1.11.1(d), as amended by 23-077 s.3; the by-law cites it as '1.1.11.1(d)', a slip, since s.1.1.11 of 150-85 is Consolidated Multiple Lot Development).
• Corner lots: the minimum interior side yard and minimum rear yard may be interchanged (s.3.1.1.2, PDF p.105).
• Landscaping: at least 30% of the lot landscaped, and at least 45% of the required or established front yard (whichever is less) kept as landscaped open space free of parking, driveways and accessory buildings (s.3.1.1.4, by-law p.88, PDF p.106).
• Residential special care facility (in a detached or semi-detached one-family dwelling or detached duplex): max 10 residents excluding staff; min lot frontage 12 m and lot area 360 m2; 200 m separation from any other such facility; annual registration; parking 2 spaces for the first 6 residents plus 1 per 2 additional residents (s.3.1.1.3, PDF p.105-106; s.2.2.1.1(h), PDF p.83).
• Commercial vehicles: no bus or commercial vehicle over 3,800 kg GVW, commercial/transport trailer or equipment parked in a residential zone, except one vehicle up to 5,600 kg GVW owned/operated by the resident inside a wholly enclosed private garage. Recreational vehicles, trailers and boats only by the resident owner, in the rear yard, a side yard (not within 1.2 m of the side lot line), a garage/carport, or on the front driveway from 1 April to 31 October (not within 3 m of the principal entrance) (s.3.1.1.8, by-law p.90, PDF p.108).
• Accessory buildings and structures (s.2.1.11.1, by-law p.50-51, PDF p.68-69): not attached to and not within 1 m of the principal building; not between the regulatory building line and the street line; not closer to a street than the required exterior side yard; at least 1.2 m from the interior side lot line when in a side or front yard; at least 0.6 m from interior side and rear lot lines when in a rear yard; all accessory uses/buildings together max 10% of lot area; max height 4.5 m and one storey; no human habitation or home occupation. A garage or carport attached to the house is not an accessory building (s.2.1.11.1(g)).
• Permitted yard encroachments (s.2.1.15, PDF p.72-73): eaves, sills, chimneys, steps etc. 0.5 m into any yard; bay windows 1 m (max 3 m wide) into front, exterior side and rear yards; balconies on detached/semi-detached/duplex dwellings 0.6 m into front, exterior side and rear yards; open or covered unenclosed porches/decks/patios not over 3 m high 2.5 m into front, exterior side and rear yards; uncovered paved patios 2.5 m into the front yard, unlimited elsewhere; open decks not over 3 m high 0.2 m into the interior side yard; fire escapes 1.6 m (rear only); wheelchair ramps 5.0 m.
• Home occupations (s.2.1.17, by-law p.55-56, PDF p.73-74): craftsperson workshop, instructor's classroom, business office, private home day care, personal services incl. hairdressing, computer services, small-goods repair, caterer; conducted wholly inside the dwelling by residents with at most one non-resident employee (who needs one on-lot parking space, tandem allowed); no outside storage, no exterior alteration, no commercial-vehicle shipping; max two clients at a time (five children for home day care).
• Setback from designated roads: on streets in the Table of Designated Road Allowances, buildings must be set back from the original centreline by the required yard plus half the designated road allowance (s.2.1.19, by-law p.57-61, PDF p.75-79).
• (H) holding prefix (s.2.1.4, by-law p.45, PDF p.63): until Council removes the (H) by amendment, the land may only be used for farming (no intensive animal, fur or fish farming), market or landscape gardening, and uses permitted in all zones under s.2.1.1. Map codes such as (H1), (H2), (H3) are numbered holding provisions set by site-specific amendments and are not described in the 2012 consolidation.
• (F) floodplain prefix (s.1.1.2.2(b)(iii), s.2.1.8, by-law p.33, 48-49, PDF p.51, 66-67): land below the regulatory flood line. No new habitable room below the flood line; no hospital, home for the aged, group home or domiciliary hostel on land more than 1 m below it, and no access to such uses below it; no bulk storage of dangerous materials below it. The same rules apply to flood-prone land outside the Special Policy Area (Map Z3). Grand River Conservation Authority approval is also required.
• Parking spaces in an RM-class zone, open or in a garage/carport, at least 2.9 m x 5.5 m; steps may project 0.5 m into the space, and in a garage or carport a wall may project 0.5 m into one side for up to 1.5 m (s.2.2.3.9-10, PDF p.93-94).
• Parking location: for detached and semi-detached houses and linear row houses, no parking stall or aisle in front of the regulatory or established building line, whichever is less; for every other residential form (apartments, cluster housing, duplexes, triplexes, maisonettes, mixed terraces) no parking other than an access driveway within 3 m of the street line, except inside the heavy-outlined areas of Maps Z4-Z6 (s.2.2.2.3(c), PDF p.89).
• Corner-lot sight triangle (15 m along the travelled edges): nothing over 0.75 m high, except on lots inside the shaded areas of Special Area Maps Z4, Z5 and Z6, where s.2.1.14 does not apply (s.2.1.14, PDF p.72); fences within 3.0 m of a street line max 0.9 m (s.2.4.4, PDF p.100).