Conservatory Costs and How Much to Borrow
The cost of a conservatory depends on its style, size, materials, and the specification of the roofing and glazing. A basic lean-to conservatory measuring 3 by 3 metres in uPVC typically costs £8,000 to £12,000 fully installed. An Edwardian square or rectangular conservatory in the same size and material runs from £10,000 to £16,000. A Victorian three or five-facet conservatory, which requires more complex construction, costs £14,000 to £22,000. At the premium end, a P-shaped or T-shaped conservatory with a solid insulated tiled roof and aluminium frames can reach £25,000 to £35,000 or beyond.
Solid roof conservatories have grown rapidly in popularity because they qualify for a better energy rating, allow year-round use, and often look more in keeping with the main house. They are also more expensive — a solid roof retrofit can cost £5,000 to £10,000 on top of a standard conservatory build. If you are upgrading an existing conservatory rather than building from scratch, factor this retrofit cost into your loan amount.
For a £15,000 conservatory funded by a secured loan over 10 years at 8.5%, monthly repayments are approximately £186. Over 7 years at the same rate, repayments rise to around £234. Many homeowners in this cost range will also consider unsecured personal loans, which are competitive for amounts up to £15,000 to £20,000 — your broker can compare both routes.
As with all secured borrowing, the amount you can borrow is limited by your available equity and the lender's combined LTV cap. For smaller conservatory loans, affordability is rarely the constraining factor — most applicants comfortably satisfy affordability criteria for £10,000 to £20,000 of additional borrowing.
Planning and Building Regulations for Conservatories
Most conservatories in England are built under permitted development rights and do not require a planning application, provided they meet the standard criteria: the conservatory does not extend beyond the rear or side wall of the original house by more than three metres (terraced or semi-detached) or four metres (detached), it does not cover more than half the garden, it is no more than 4 metres in height, and it does not form part of a listed building or fall within a conservation area.
A key advantage of conservatories over full extensions has historically been their exemption from building regulations. A conservatory is exempt if it is at ground level, the floor area does not exceed 30 square metres, it is separated from the rest of the house by external-quality walls and doors, and it has an independent heating system (not connected to the main system). If these conditions are not met, building regulations approval will be required.
Modern solid-roofed conservatories often fall outside the building regulations exemption because the roof is not primarily translucent glazing. If you are specifying a solid tiled roof, confirm with your installer whether building regulations approval is required — responsible installers will handle this as part of the project. Lenders may ask whether the works required planning permission or building regulations approval and will want evidence of compliance.
In Scotland and Wales, permitted development rules differ from England, and you should check with the relevant planning authority before assuming no permission is required. Northern Ireland has its own planning framework that broadly mirrors England but with some local variations.
