Types, costs and structural requirements
Through-floor lifts are installed through an opening cut in the floor between two storeys, providing access for wheelchair users or people unable to use stairs or stairlifts. There are two main types: platform lifts (open platform or platform with half-height gates) and enclosed cabin lifts (fully enclosed with automatic doors on both levels). Platform lifts — the more common DFG-funded option — consist of a scissor-jack or direct-acting hydraulic mechanism raising an 800mm × 1,100mm platform through a standard 900mm × 1,100mm floor opening. Suppliers: Stiltz Duo (home platform lift, £8,000–£11,000 installed), Terry Lifts Harmony (£9,000–£13,000), Handicare Freeway (£8,500–£12,000), Pollock Lifts (£10,000–£14,000). The platform size limits use to a single standing or seated person — a manual wheelchair user can use a platform lift, but a powered wheelchair user requires a larger opening and a wider platform (minimum 900mm × 1,400mm). Enclosed cabin lifts — with automatic sliding or folding doors on both levels, enclosed car, handrails and emergency call system — provide a more refined finish suited to private residential installations where aesthetics matter. Cost: £14,000–£22,000 installed. Through-floor lift installations require a structural engineer to design the floor opening where a joist must be cut — a trimmer joist arrangement is standard. This structural works package typically costs £1,500–£3,000 and takes 1–2 days by a structural carpenter. The lift mechanism sits in a pit or base unit on the lower floor and a landing platform on the upper floor. Electrical supply: a dedicated 13A or 16A circuit to the lift mechanism is required, notified under Part P Building Regulations.
Building Regulations, planning permission and DFG
Through-floor lifts are subject to Building Regulations Part M (Accessibility) and require Building Control approval. Most London councils require a Building Regulations application for through-floor lift installation — either a Full Plans application (submitted before works, recommended for DFG-funded projects) or a Building Notice (submitted at start of works). The lift must comply with BS EN 81-41:2010 (limited use limited speed lifts). Lift suppliers provide the CE-marked compliant lift unit; the installer submits the installation certificate to Building Control on completion. Building Regulations application fees: £200–£400 for a through-floor lift in London. Planning permission is not normally required for a through-floor lift within a dwelling — it is an internal alteration. Listed Buildings require Listed Building Consent for any structural alteration including floor opening formation. Disabled Facilities Grant funding: through-floor lifts are the single most costly common DFG adaptation. Where the assessed cost exceeds £30,000 (typically for enclosed cabin lifts with significant structural works), top-up funding from Better Care Fund discretionary grants or charitable sources is required. Most London borough DFG-funded through-floor lift projects fall within the £30,000 cap when using platform lifts (£8,000–£14,000 lift plus £2,000–£4,000 structural works). The OT will recommend a through-floor lift over a stairlift where the user cannot safely transfer to and from a stairlift seat (e.g., full-time wheelchair users, Parkinson's patients with freeze episodes, post-stroke patients with limited upper body strength).
