Loft Conversion Prices in the London Area

Guide & Prices 2018 / 2019

Cost of loft conversions in London is generally between £35,000 and £60,000 depending on the nature of the design, level of project management, and type of conversion.

Not every quote is the same, watch the video to uncover what the potential hidden costs could be. Call us for a free quote, tel 020 8088 0809

prices for a loft conversion in London

Core Loft Cost inc. VAT (Excluding Tiling, Decoration & Carpets)

Dormer Conversion - £40,000
Mansard Conversion - £42,500
L Shape Dormer Conversion - £45,000
Hip to Gable Conversion - £52,500

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costing a loft conversion with Visionary Lofts

Example of Additional Cost inc. VAT

Designs and Planning Permission - £1,500
Tiling - £2,500
Decoration - £3,000
Carpet Fitting- £500

Loft Conversion Options

Loft Conversions are a great investment, as not only do they increase the size of your home by providing a substantial amount of living space, but they can also increase the value to your property by as much as 30%. That being said, if you are thinking about converting your loft into a brand new living space then you will probably also be wondering - ‘how much will it all cost?’ Skip the complimentary consultation form below to read on or fill it in to save time and we'll call you back with advice.

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The price of a Loft Conversion is understandably a crucial factor in deciding whether or not to embark on such a project. At Visionary Lofts  we appreciate this, and have therefore produced a guide to help you familiarise yourself with the average cost of a Loft Conversion in London, so you know roughly what to expect before getting a quote. 


Before determining the average cost of a Loft Conversion it is important to note that different factors can affect the overall price of your conversion, and are well worth bearing in mind when considering the general cost of the project.


Such factors include…

  • Freeholder / Leaseholder – Do you own the loft space? Do you need to purchase the loft space from a freeholder?
  • Party Wall Matters – Will you need party wall surveys before commencing the works?
  • Loft size – How much roof space you are you wanting to convert?
  • Loft suitability – Does your loft need to be additionally strengthened to facilitate the conversion?
  • Extra features – Do you want to add skylights, under floor heating or maybe a wet room bathroom?
  • Fire Regulations – Does the rest of your house comply with fire regulations? You may also need to budget for fire doors, alarms and even a sprinkler system!
  • Type of Contractor – Who do you want to trust with working in your home? A man and a van or a professional loft conversion specialist?
  • Site Access / Logistics – How accessible is the roof? This can impact the cost of parking, waste removal, materials storage and scaffolding

The Type of Loft Conversion is the key factors influencing the price of your Loft Conversion. Generally speaking there are four main types of loft conversions that are commonly undertaken in London. A Dormer conversion, Mansard Conversion, L Shape Dormer Conversion and a Hip to Gable Conversion. To help you budget for your project we have produced a table that depicts the average price of each of these types of Loft Conversion in London, including the cost of a mansard. We have also put together a list of other common items that you should budget for.

Although it has hard to put an exact price on a Loft Conversion due to the factors stated above we hope that this helps to give a rough approximation of how much you should be expecting to pay for your conversion. 

Alongside the price of a Loft Conversion, time scale and project management are two important factors to also take into consideration. The time-scale of a Loft Conversion can be split into two sections: the first being the Initial planning of the project, and the second being the actual time it takes to build it.

Planning and Party Wall Agreements–

Generally speaking planning permission (if required) will  take 8 weeks to be approved although you should also allow for an additional 4 weeks for the actual surveying and designing of your loft. During this same 12 weeks you can also issue the party wall structure notices to your neighbours while waiting for your planning approvals.

Construction –

Although timescales are estimates, it can be useful to have an approxiamte indication as to how long building work is due to take place and if there will be disruptions to your house as a whole. As such, we have included a rough timeline to exemplify how long a standard Loft Conversion usually takes so that you know what to expect.

Typical Schedule

Weeks 1 and 2

  • The first week of work is usually the preparation stage, whereby site set up and demolition works are undertaken.
  • This includes erecting of scaffolding and delivering a skip if necessary.
  • At this stage the existing roof structure will be stripped out and the new structural steel work will be installed. The works will mainly happen from the outside with minimal disruption to the rooms below.

Weeks 3 and 6

  • Within this time the work generally moves inside the house, however the roofing team will also need to access the property via the roof, which provides little disruption to the rest of the house.
  • During this time the timber structure, staircase and glazing is installed, closely followed by internal stud walls and 1st fix services as the project progresses.

Weeks 7, 8 & 9

  • The first part of this stage involves the installation of insulation and plasterboard.
  • Following on from the plastering works is the completion of carpentry works, electrics and plumbing if required.
  • Finally, decoration and tiling of the new conversion may begin which, once finished, results in the completion of your Loft Conversion.