How Much Will a Loft Conversion Cost?

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There are a variety of reasons to expand your living space with a loft conversion. A loft conversion can not only create extra space but can also raise the value of your home. Whether you are embarking on a conversion due to lack of space of lack of selling potential, budgeting is the first step on the loft conversion ladder.

One of the most frequently asked questions when embarking on a loft conversion is the estimated cost. The cost of a loft conversion will vary from project to project and will of course depend on the scale of your personal project. The cost of a loft conversion can be affected by many factors; here is a step by step guide.

The following factors come in to play when trying to set a ball park figure for your conversion:

Your House

The type of property you live in can affect the cost of a conversion. For example if you live in a two bedroom house or a five bedroom house the price will differ. In terms of your actual property the following aspects should be taken into consideration:

  1. The size and type of your home
  2. The roof type and condition
  3. Any plumbing that may need to be relocated
  4. Any complications such as chimneys or unusual layouts

The Scale of Your Project

All loft conversions start with nothing but a few ideas and once the ball is rolling it is easy to get carried away in terms of the size of your project. You may begin with the vision of a simple yet liveable space but as your conversion starts to take shape it is easy to decide on a more complex layout. A conversion is more than a practical venture; it involves a lot of imagination. Many look at a conversion as the perfect opportunity to create a luxurious space in their home or to create a unique selling point. The more complex the layout becomes the more expensive it becomes. Loft conversions can transform an unused space into more that just a usable space. The possibilities are endless; you could make an extra office space, a home gym or an extra bathroom. You don't have to settle for one room, you could have a bedroom with an en-suite. Obviously sizable changes to your attic space can lift the price of your conversion considerably.

The Type of Conversion

A basic conversion using roof windows such as those manufactured by Velux will be cheaper than a conversion that uses dormers. Sometimes the roof is made bigger by a hip to gable conversion, obviously the bigger and more complex the work, the higher the cost. Take a look at our page on loft conversion types for more information.

The Electrical Works

All loft conversions involve some electrical work, namely for lighting, power sockets and smoke alarms. The amount of electrical work will depend on the design, size and intended use of the conversion. For example a single simple room may require lighting and power sockets, while two bedrooms and an en-suite will obviously require more work and materials, and therefore cost more.

Lighting can be as basic or as complex as you wish so you can choose solutions that will not stretch your budget. Seek advice on the best lighting solution to meet your individual needs. Halogen downlighters are a popular choice, see our blog post that looks at LED bulbs for downlighters.

A mains wired smoke detector is an essential safety item and will be required for your conversion to meet building regulations.

The Plumbing Works

The plumbing is one area that can be subject to large variations in terms of cost. Quite often at the very least there will be a cold water and expansion tank that will need to be relocated. Many people decide to have combi boilers installed so that water tanks are no longer required. Here is a list of the main factors to consider regarding the plumbing:

  1. Are there any existing water tanks that need to be moved?
  2. Are you having a new boiler installed?
  3. Are you having an en-suite installed?

The Choice of Windows

The more natural light you require the more money you are going to have to pay for the privilege. The amount of windows you want to install in your loft space and the chosen size will affect the price of your conversion. Velux windows come in a wide range sizes and finishes; browse the Velux website to find the best windows for your individual project.


Flooring is not something to be skimped on in terms of price. With flooring you get what you pay for and high quality flooring can provide the finishing touch to a conversion. Many people opt for soft floorings rather than wooden to minimise any noise. The amount of budget you will need to set aside for flooring will depend on your personal preferences and type of flooring chosen.

DIY Conversions

Taking on part of the conversion yourself can help to keep your expenses low. The amount of work you take on will depend on your level of DIY experience. We have a dedicated an area of this site to DIY Loft Conversions. There are currently a good range of books available for general DIY and loft conversions. We selected some of the best books available form Amazon, take a look at our books page to see what is available to buy online.


While we cannot give you an exact figure for your loft conversion this guide will help you to identify and understand where the cost lies. Most good loft conversion specialists will be happy to provide written quotations, use our find a loft conversion specialist page to get in touch with a local expert.