Backyard design and build

Design and build means one contract covering the drawing and the construction, and for most Ottawa back gardens it is the right way to buy. The reason is sequencing. A back garden involves excavation, drainage, base preparation, masonry, carpentry, planting and electrical, and one party owning the whole sequence is worth paying for.

Step one: locates, and this one is the law. Before any excavation, a locate request through Ontario One Call is required in Ontario. It is free, it has to go in at least five business days before you dig, infrastructure owners have five business days to respond to a single address request, and a locate is valid for at least 60 days. Follow each owner's own instructions, because the hand-dig zone around a marked line differs by utility.

Step two: levels and drainage first. Water leaves before anything is built. The City is explicit that a homeowner may not change the grading of a property, that water must follow approved drainage patterns and cannot be directed onto a neighbouring property, and that ditches must not be altered (City of Ottawa Landscaping Education Guide). Within those rules, the fall across a patio, the swale behind it and where the downspouts discharge are all set at this stage, and they are all much harder to change afterwards.

Step three: excavation and base. The base is the part you never see and the only part that decides whether the work is still flat in ten years. On clay, expect a deeper excavation and a thicker granular base than a sandy site would need, with a geotextile separation layer between the clay and the stone so the two do not mix. Compaction in lifts, checked, is what keeps a patio level through the freeze and thaw cycle.

Step four: hard surfaces and structures. Paving, steps, walls, a deck, a pergola, a fire feature. Anything that carries load or retains soil needs footings below frost, and the Building Code's foundation depths reach as much as 1.2 m below grade in clay soils (OBC 9.12.2.2). A retaining wall over 1,000 mm of exposed height needs a building permit and an engineer's design confirming compliance with Part 4 of the Building Code, with a guard where the drop exceeds 1.0 m (the permit rule).

Step five: planting, irrigation and lighting. Sleeves under any paving first, then soil preparation, then planting, then lighting. Soil is where most planting budgets go wrong: Ottawa clay subsoil is not a growing medium, and 300 to 450 mm of amended topsoil in beds is the difference between plants that establish and plants that sulk.

How long it takes. A modest back garden, a patio, a few beds and a fence, is two to four weeks on site. A full build with walls, steps, a deck, lighting and irrigation is six to twelve weeks. The season is the real constraint: the ground in Ottawa is frozen or saturated from late November to mid-April, so the build window is roughly May to early November and books out early.

What it costs in 2026. Indicative ranges. Paver patios are commonly $25 to $45 per square foot installed, sod is $0.35 to $4 per square foot and overseeding $0.10 to $0.80 (RenoQuotes 2026). A modest back garden with a 300 square foot patio, planting beds and sod is realistically $15,000 to $30,000 in this market. A full build with a raised patio, steps, a seat wall, lighting and irrigation is commonly $45,000 to $120,000. What moves the number most: how much material has to come out and go back in, access for machines to the rear yard, wall height, and the paving unit chosen. Add 13 per cent HST.

What makes an Ottawa back garden different. Access and clay. Inner-city lots in Hintonburg, the Glebe and Old Ottawa South are narrow, and a machine often cannot reach the back garden at all, so material moves by wheelbarrow through a 900 mm gate. That can add thirty to fifty per cent to an excavation cost and it should be identified at the quote. The clay is the other half: it drains slowly, it heaves, and it means deeper bases, geotextile and real drainage design. Add the salt line along the driveway and the front walk, and the plant list within three metres of any hard surface has to be salt tolerant.

Who should do the work. No provincial licence exists for landscaping in Ontario, and the title Landscape Architect is the only protected one, restricted to full members of the OALA (OALA on the title). What you can check instead: liability insurance limits, WSIB coverage for the crew, a professional engineer in the PEO directory for any wall over 1,000 mm, and a certificate of qualification for whoever does the lighting electrical. Ask whether the crew is employed or subcontracted, because on a twelve-week build that decides who you talk to when something is wrong.

What to ask before you hire. Has a locate been requested, and when does it expire. What is the excavation depth and base thickness, and is geotextile included. How is water leaving the site, and does anything discharge toward a neighbour. Is any wall over one metre, and who is the engineer. Can a machine reach the back garden, and if not, is hand excavation priced in. How much topsoil is going into the beds. What is the written warranty on settlement, on plants, and for how long. And is the price fixed or an allowance.