Updated October 2026
MyHouseDesigner designs duplexes, triplexes and fourplexes on Richmond single-family lots, from the first zoning check through to the drawings you submit for a building permit. If your lot was moved into Richmond’s new small-scale multi-unit housing zone, you may be able to build three or four homes where one house stands today, and in most cases the City says the project needs a building permit rather than a rezoning.
At a glance
| Service | Duplex, triplex and fourplex design and building permit drawings |
| Area | Richmond, BC: Steveston, Seafair, Broadmoor, Terra Nova, Blundell, Garden City and other residential neighbourhoods |
| Included | Zoning and lot review, concept layouts, design development, permit drawing set, coordination with engineers, responses to plan-review comments |
| Typical steps | Lot check, concept, consultants, permit set, submission, revisions |
| How to start | Call 778-488-8553 or request a free design quote |
How many units can I build on my Richmond lot?
Under Richmond’s small-scale multi-unit housing (RSM) rules, a lot of 280 m² or less can generally hold up to three units, a larger lot up to four, and a lot over 281 m² within 400 m of a frequent-service bus stop up to six. Secondary suites can be added on top of that, limited to one per principal unit.
Council moved close to 27,000 single-family and duplex lots into the new framework on June 24, 2024, but not every lot qualifies. The City’s Small-Scale Multi-Unit Housing bulletin lists the exclusions, including properties in the Agricultural Land Reserve, protected heritage properties, lots larger than an acre, lots without city water or sewer, and lots inside a Transit Oriented Area. Floor area, height, yards, building separation and lot coverage are all set out in that bulletin, and they decide what actually fits.
In practice, the unit count allowed on paper and the number that works on your lot are often different. A 33-foot-wide lot in Steveston and a wide Seafair lot with a back lane are very different design problems, even with the same zone.
Do I need a rezoning or just a building permit?
For most RSM projects on a single lot, Richmond says a building permit is all that is required. A development permit is also needed if the site is in an environmentally sensitive area, if a building pushes into the RSM rear yard setback, or if the lot is irregular rather than rectangular.
Combining two or more lots usually means a rezoning to a different multi-unit zone, which is a longer, council-level process. We tell you early which route you are on, because it changes the schedule and the consultant list.
Can a building designer handle my project, or do I need an architect?
Richmond requires an architect for projects with five or more units, so our work here focuses on duplexes, triplexes and fourplexes, with or without suites. If your lot qualifies for five or six units, we will say so plainly and explain how the work would be split.
Our article on architects versus building designers in BC goes into where that line sits and why.
What makes Richmond multiplex design different?
Richmond is flat, low-lying and built on the Fraser River delta, so the ground and the flood rules shape a multiplex here more than slopes or views do.
- Floor elevations. The City’s Flood Plain Designation and Protection Bylaw No. 8204 sets minimum elevations for habitable space. That affects how high the main floor sits, how you step up to front doors, and whether a ground-level suite works at all.
- Soft soils. Much of the city sits on soft delta soils. A geotechnical engineer is often part of the team, and foundation design can influence the building’s shape.
- Parking and lanes. On lots 15 m or wider with three or more units, Richmond wants parking at the rear. With a lane that is straightforward. Without one, the driveway, garage and unit layout have to be solved together.
- Trees. The City’s guidance is that tree removal is discouraged and replacement is required. A mature tree in the back yard can decide where the rear building goes.
- Energy requirements. New homes must meet the BC Energy Step Code level the City currently applies, so wall assemblies and window choices get settled during design, not left for the builder.
Want to know what your lot can hold? Tap to call 778-488-8553 with your address.
How does the design process work, step by step?
We work in stages so you can make the expensive decisions with the right information in front of you.
- Lot review. We confirm the zone, lot area, width, lane access, frequent-transit status, and any exclusions or development permit triggers.
- Survey and records. You order a topographic survey; we ask for any past permit records for the property.
- Concept options. We sketch two or three arrangements, for example front-back buildings, a side-by-side duplex with suites, or a single fourplex building, and compare floor area, parking and outdoor space.
- Consultants. We bring in the structural and geotechnical engineers, an arborist if trees are involved, and an energy advisor, and coordinate their input into the drawings.
- Design development. Unit plans, elevations, sections and finished floor heights are fixed, with your input at each round.
- Permit set and submission. We assemble the drawing set to the City’s current submission requirements.
- Plan review. When reviewers send comments, we revise and respond so the file keeps moving.
How long approval takes depends on the City’s workload, the project and how complete the submission is, so we do not quote a date. For a broader look at how SSMUH affects value and layout choices, see our guide to getting the most from BC’s multiplex zoning, or our overview of multiplex design services across Metro Vancouver.
Who is this service for?
- Owners of an older Richmond house who want to replace it with a duplex or fourplex and keep one unit for themselves.
- Families planning homes for parents and adult children on one lot, each with its own entrance.
- Small builders who need permit drawings for a three- or four-unit project on a single lot.
If you would rather build one custom house, read our piece on designing a modern house in Richmond, or see the Richmond custom home design and permit drawings page from our sister team.
What mistakes do Richmond owners make with multiplex projects?
- Counting units before checking the lot. The maximum is a ceiling, not a promise. Width, lane access and rear parking often decide the real number.
- Forgetting floor elevation. Raising the main floor to meet flood requirements changes stairs, entries and the overall height, so it belongs in the first sketches.
- Assuming the neighbour’s project applies to you. Transit distance, lot shape and exclusions differ from one lot to the next.
- Bringing in consultants late. A geotechnical or arborist report that arrives after the design is drawn can force a redesign.
Richmond duplex and multiplex design FAQ
Most former single-family lots were moved into it in June 2024, but some were excluded, such as ALR land, protected heritage properties and lots in Transit Oriented Areas. We confirm your lot’s zoning at the first step.
Richmond allows one secondary suite per principal unit, and suites cannot be stratified. Whether a suite fits depends on floor area, floor elevation and layout, which we test during the concept stage.
Richmond removed residential parking minimums on lots that qualify for up to six units near frequent transit; other RSM lots have their own requirements, which we check for your address. On lots 15 m or wider with three or more units, parking goes at the rear.
Almost every multiplex needs a structural engineer, and in Richmond a geotechnical engineer is common because of soft soils. An arborist and an energy advisor are often needed too. We tell you which apply once we have seen the lot.
It depends on the number of units, the lot and how many consultants are involved. Send us your address and goals and we will give you a free quote for your project.
Start your Richmond multiplex design
Send us your address and what you hope to build, or call to talk it through.
We reply within one business day.