Multifamily (Multifamily Housing)
Multifamily housing is a building or scheme of many separate homes, usually apartments, owned and managed as one rental asset. The term is American. In the UK the same asset is called build to rent (BTR), the planning term, and the houses end of the market is called single-family rental.
What is multifamily housing?
Multifamily describes the shape of the asset: many homes under one roof or one scheme, rented to separate households. In 2018 Savills put it simply as blocks of apartments designed specifically to rent, set against "single family", meaning individual houses designed specifically to rent.
The word has no UK statutory definition. The National Planning Policy Framework defines build to rent instead: purpose built housing that is typically 100% rented out, in flats or houses, in single ownership and management control. Multifamily is the trade label for the flats-and-blocks part of that.
The US has a number for it. The US Department of Housing and Urban Development (HUD), the American federal housing agency, defines a multifamily project in its regulations as not less than five dwelling units on one site. HUD has no standing in the UK, and that figure belongs to its loan programmes, so it should not be read as a UK rule or a universal one.
Why multifamily matters for student accommodation and build to rent operators
Most investor reports, software vendors and benchmarking data written for this asset class come from the US and use its vocabulary. An operator reading them needs to know the term maps to UK BTR, and that US lease structures, deposit rules and eviction law do not carry over. UK tenancy rules are covered under Renters' Rights Act.
Scale is the reason it matters commercially. UK BTR stood at over 146,700 completed homes at Q4 2025, with a further 152,100 under construction or in planning. Operators running several buildings are running a multifamily portfolio, whatever they call it.
Purpose-built student accommodation (PBSA) is also made up of many rooms under one owner and is usually described separately, because the tenancy cycle, the customer and the booking pattern differ.
Key takeaways
- Multifamily is a US term for a building or scheme of many rented homes under one owner. The UK planning term is build to rent.
- In UK trade use it means the apartment-block side of BTR. The houses side is single-family rental.
- There is no UK statutory definition of multifamily. The five-unit threshold comes from US federal housing regulations.
- UK BTR stood at over 146,700 completed homes at Q4 2025.
How Cloudfox Helps With Multifamily
In a multi-building portfolio every commercial question is asked per building and per room or flat type: how many enquiries, which building, what is available. Cloudfox sets up HubSpot with the building as its own record, so enquiries are assigned to the right team automatically, and connects the property management system so availability and occupancy for each building flow in without re-keying. Find out more at cloudfox.it/what-we-do.
Frequently Asked Questions About Multifamily
Is multifamily the same as build to rent?
Close, not identical. Build to rent is the UK planning term and covers flats and houses. Multifamily usually means the flats-and-blocks part of it.
Is student accommodation multifamily?
It shares the structure of many rooms under one owner, but the sector treats [PBSA](/glossary/pbsa) as its own asset class with its own tenancy cycle.
How many units make a building multifamily?
No UK rule sets a number. In US federal housing regulations a multifamily project has not less than five dwelling units on one site. Other US documents use different thresholds.