The half duplex is the form inner-city redevelopment settled on, and Altadore is where Calgary produces the most of it. A builder takes a post-war lot, replaces the original house with two attached homes, and each half sells on its own title — commonly three storeys, or two above a developed lower level, with a lane garage behind and frequently a lower level built to be suited. On the MLS® these are recorded as semi-detached, which is why this search and the detached search return different homes on the same streets. several semi-detached homes are for sale.
Altadore is one of the most actively redeveloped communities in the city, and the half duplex is what most of that redevelopment looks like. It exists because the economics of an inner-city lot work better with two homes on it than one, and the result is a form that puts new construction, a walkable Marda Loop address and a downtown commute of roughly fourteen minutes inside a budget that a comparable new detached infill on the same street would not. What you give up is the side yard and one wall. What you get, on most of these, is a purpose-built new home with current mechanicals, a developed lower level, and a lane garage — on a street where Altadore School, River Park and the 33rd Avenue shops are all within a walk.
The two halves of a pair are rarely equal. Sun exposure, which side gets the wider drive or the better garage access, corner position, and which half faces the neighbouring lot all move value, so compare the specific half rather than the address. Ask who built it and ask for the new-home warranty documentation, because build quality across inner-city infill builders is genuinely uneven. Listen for the party wall — sound separation is a real point of difference and is worth testing before you remove conditions. If a suite is part of the pitch, treat its legality as unproven until permits and the City's registry say otherwise. And check what the lots on either side are zoned to become, because on an actively turning block the framing crews may not be finished with your street.
Measured over September 2025 to August 2026 from MLS® data, on 55 semi-detached sales. Aggregates only, for a stated window; the listing counts elsewhere on this page are read live.
55 of the 169 Altadore sales in the window were half duplexes. That is the redevelopment rate showing up in the sales record.
The detached median over the same window was $1,390,000, so a half duplex traded about 17% below it.
Detached ran 1,999 sq ft over the same window, so the half duplex is not automatically the smaller home.
Detached in Altadore ran 18 days over the same window, so half duplexes moved in line with the houses beside them.
Measured against the last asking price, so it understates what a seller gave up if the price was reduced on the way.
Two homes sharing one wall. In Calgary a semi-detached home is usually freehold: each half sits on its own titled lot with no condominium corporation, which is the part buyers most often get wrong. Some are bare-land or conventional condominiums instead, with a fee and a board. The title and the listing’s ownership type settle it — two identical-looking halves on the same block can be held either way.
A single inner-city lot that can be redeveloped as two attached homes carries its land cost across two sales instead of one. That arithmetic is what has been rebuilding these streets, and it is why the newest housing in Altadore is more likely to be attached than detached, and why a half duplex here is often the newer, larger and better-finished home on the block rather than the compromise.
Ask what the wall is built of and how far it goes: a wall that runs to the underside of the roof deck, with proper fire separation and no shared framing, is a different home to live in than one that stops at the ceiling. Sound transfer is the most common regret. Where the two halves are held freehold, check whether a party wall agreement is registered on title and what it says about maintenance, insurance and access for repairs.
Confirm the water, sewer and gas services are separate rather than shared through the neighbouring half, and find out who owns the fence, the walkway and the drainage between the two properties. On a new build, ask for the Alberta New Home Warranty documents and confirm what remains of the coverage — it runs from the date the home was first occupied, not from your possession date.
The streets buyers ask about most here are the infill core — the interior streets where redevelopment runs hottest, the River Park edge — the western streets against Sandy Beach and the Elbow valley, the Marda Loop edge — the northern blocks along 33rd and 34th Avenue, the luxury infill streets — where architect-designed builds set the community's ceiling and the remaining originals — post-war and character homes priced as land positions.
Nearby amenities include the Marda Loop shops and restaurants on 33rd and 34th Avenue, the Marda Loop Safeway, River Park and the Sandy Beach off-leash valley. Access is via Crowchild Trail, 14 Street SW and 33 and 34 Avenue SW.
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Talk to a REALTOR® All Altadore listingsListing counts on this page are read live from the MLS® feed each time it loads. Market figures cover August 2025 to July 2026. How we calculate these figures.