In Cambridge a House Can Carry Three Units Under By-law 26-007, Unless It Sits in the Grand or Speed Floodplain

What By-law 26-007 allows on a Cambridge lot

Two zoning by-laws now share the city. Phase One of the Comprehensive Zoning By-law, By-law 26-007, was enacted and passed on 3 February 2026 and came into effect the same day; it repealed the residential zones of the old By-law 150-85 except for lands under transition rules or shown as deferred on the maps, where the 2012 consolidation of 150-85 still governs. Before you plan anything, confirm which by-law your lot sits under on the City's interactive zoning map.

Section 4.19 is the part a homeowner or landlord needs. Additional residential units are permitted with a detached house, semi-detached house or street townhouse on a parcel of urban residential land. A maximum of two ARUs are permitted per lot, as either two attached units or one attached and one detached; the City's own summary calls that three units in total. Each ARU needs one additional parking space, and that space may be tandem, meaning one car parked behind another on the existing driveway. No new driveway or vehicular access may be created to serve an ARU, so the count has to work on the pavement you already have.

Where municipal water and sewer are available, the house and every ARU must be connected to services of adequate size. The entrance to an ARU may be no more than 30 metres from the street unless the unit is reached by a lane that meets Fire Access Route requirements. An ARU is not permitted on lands in the Floodway (F) Zone or any Floodplain Overlay Zone, and a group home lot cannot carry one. Everything else is about entrances, paths and the detached-unit envelope, covered below.

Entrances, garden suites, permits and fees

An attached unit's entrance matters in Cambridge because the by-law regulates the path to it. Where the door is in the interior side yard, it must be at least 1.2 metres from the side lot line. Where the entrance is a side or rear door, an unobstructed pedestrian path 0.9 metres wide and 2.1 metres high must run from that door to the street; only steps or landings up to 1.1 metres deep and 0.6 metres high may project into it, they must keep access to the rear yard, and the path must keep storm water draining on the lot under the Site Alteration By-law. A side-yard separate entrance is the cleanest way to satisfy all of that.

A detached ARU may sit in the interior side, exterior side or rear yard, 1.2 metres from the interior side and rear lot lines, 0.6 metres from a rear line on a lane or through lot, and 4.5 metres from the house. Height is 4.5 metres on a lot with under 21 metres of frontage, rising to 6.0 metres on 21 metres or more when the suite is 3 metres from every lot line and 6 metres from the house, or on lane and through lots. The footprint is the lesser of 100 square metres or 15 per cent of the lot, with the same 0.9 by 2.1 metre path to the street.

Every ARU needs a building permit under the Ontario Building Code and occupancy approved by the City's Building Services Division; applications go through the City Application Portal at permits.cambridge.ca, fees are invoiced after submission and must be paid before the application is complete, and a $100 re-inspection fee has applied since January 2024. The City and Region collect no development charges on an ARU. The City launched a Housing Accelerator Fund grant of up to $10,000 per property on 1 November 2024 toward service upgrades, drawings and construction; confirm with the City that funding remains open.

The Grand, the Speed and the GRCA

Cambridge exists because of its rivers. Shade's Mills was founded in 1816 where Mill Creek meets the Grand, Preston grew around an 1806 sawmill and 1807 gristmill, the oldest continuously operating industrial site in the region, and Hespeler's industry lined the Speed from 1845. On 17 May 1974 the Grand rose from its usual half-metre to more than 5 metres through downtown Galt, flooding streets to about 1.2 metres and roughly 75 businesses. The Grand River Conservation Authority has owned and maintained dikes protecting low-lying Galt since, and Cambridge (Galt) is one of eight Special Policy Areas in the watershed where development that would otherwise be refused is allowed under its own criteria: structural flood proofing, safe access and egress, and the nature of the use.

The GRCA regulates river and stream valleys with their floodplains and slopes, wetlands and steep slopes under Ontario Regulation 41/24, and adds a 15 metre allowance to the riverine flooding hazard and 30 metres around wetlands. If the Map Your Property tool puts any of your lot inside the Regulation Limit, an addition, garage, shed, deck or grading needs a GRCA permit on top of the City's building permit; the authority says a permit usually takes four to six weeks. Its fee schedule, effective 26 April 2024, prices minor development such as a minor addition at $465 and standard development such as a major addition at $675.

The City's zoning carries the same line. Floodplain Overlay Zone 1 covers built-up land in a one-zone floodplain or floodway; there, only minor additions and alterations to existing buildings are allowed, with no new dwelling units and no new floor space, basements included, below the existing first floor. Zone 2 is the flood fringe of a two-zone area. Neither takes an ARU.

Heritage cores and housing stock, era by era

Cambridge was assembled on 1 January 1973 from Galt, Preston and Hespeler, three mill towns that had grown separately since the early 1800s. Galt earned the name the Manchester of Canada; Hespeler headquartered Dominion Woollens and Worsteds, one of the largest textile producers in the country. That history sits on the ground as three century-house cores, and the City keeps a Heritage Register of properties designated individually under Part IV of the Ontario Heritage Act, designated within districts under Part V, and listed but not designated; an interactive map is the digitized register, and [email protected] will confirm a property's status. There are three Heritage Conservation Districts: Main Street in Galt, whose plan dates to 1984 and is bounded by Main, Ainslie, Water and Imperial Lane; Blair Village, designated in 2002; and Dickson Hill, whose 2005 plan covers City-owned public spaces. The City has studied a wider Galt Core district since 2020; check the Heritage Register map for the boundary in force today before you draw. Inside a district, alterations to heritage attributes, additions and demolition need Council approval, and owners of designated properties can claim a heritage grant of up to half the cost of conservation work, to $7,500 a year.

The census shows what came after the mills: 72,383 people in 1976, 92,772 in 1991, 110,372 in 2001 and 138,479 in 2021. That growth is the subdivision belt the City maps as Shades Mills, Eastview and Branchton Park in Galt, Preston Heights and Langs Farm in Preston, and Silverheights and Centennial in Hespeler. For a basement suite the era sets the work: the Code allows 1.95 metres of ceiling in a basement unit, an egress window of 0.38 square metres with a 460 millimetre openable width and a sill no more than 900 millimetres up, 30-minute fire separations and interconnected smoke alarms. Post-1973 basements usually clear the height; century cores in Galt, Preston and Hespeler often do not.

How HMH sequences a Cambridge job

HMH Construction is a licensed, WSIB-covered residential general contractor with offices in Mississauga and Milton. Before we quote a Cambridge address we pull the zone and any F, F1 or F2 overlay on the City's zoning map, run the lot through the GRCA's Map Your Property tool, check the Heritage Register map, and put a tape on the driveway and the basement ceiling. If the lot is under the deferred or transition rules of By-law 150-85 rather than 26-007, we say so, because the unit count and parking answer changes.

The separate basement entrance is the job most Cambridge suites start with, and we build it to section 4.19.1: the door at least 1.2 metres off the side lot line, a 0.9 metre clear path to the street with the landing held to 1.1 by 0.6 metres, and grading that keeps storm water on the lot. Engineering, permit, excavation, forming and pouring the stairwell, door and sill, waterproofing and the drain tie-in: the site work is done in three days. Behind it we design, permit and build the legal basement apartment to the Building Code checklist the City's inspectors work from, then carry it through to occupancy approval.

We build detached garden suites to the 100 square metre, 4.5 or 6.0 metre envelope, garage conversions and multi-unit conversions, plus kitchens, bathrooms, finished basements, whole-home renovations, home and second-storey additions, and commercial fit-outs. Call 905-749-4608 for a straight read on your lot.