How to: Do a Loft Conversion…

Often branded as a more cost-effective, less disruptive way to add space to a home and with moving costs so high, many are turning to loft conversions in the hunt for that extra bedroom or two. Bearing in mind that bedrooms are typically worth ‘more’ than the extra living space created by a side addition,  it is certainly an attractive consideration when thinking about return on investment. Some estimate that loft conversions can add up to 30% to the value of a home.

The transformation of a loft certainly has appeal in terms of ‘the build’. Unlike other extensions,  loft conversions can be completed from the outside, meaning that families can reside in-situ for the course of the works. The works involved also typically take less time than traditional ground floor and basement builds, with a standard conversion taking around 8 weeks to complete.

How much should I budget?

A simple ‘roof light’ conversion, whereby enough space is already provided in the loft and only a new roof light and staircase is required, can be expected to cost around £20,000. However, prices for the more popular ‘dormer’ conversion, which will increase usable space by including a protrusion to the side of the roof, tend to start at around £25,000. ‘Hip to gable’ conversions (only suitable for end of terraced, semi-detached and detached properties) and ‘mansard’ conversions (suitable for any property type) are again dearer, but in turn add significantly more space. As an example, a typical hip to gable conversion can be expected to start from £30,000 and a mansard conversion will have a price tag starting from around £35,000.  

If the above is palatable, below are some of the basics you’ll need to know before embarking on your project:

Is a loft conversion feasible?

The easy way to see if a loft conversion is possible is to note whether your neighbours have embarked on a similar scheme. Look at the other properties in the street and if you can spot any roof lights or dormer windows, then the chances are that you will be able to carry out a loft conversion of your own. Surveyors, builders and architects will also be able to confirm if your ideas are feasible.

A loft conversion is made easier if you own the (a) house, and you are not changing the footprint of the dwelling. If this is the case, then a loft conversion would tend to fall within your permitted development rights. That said, there are still a number of specific conditions that need to be adhered to and these can be found here:

If you own the (a) top floor flat only and/or are planning to alter the loft space footprint, you will certainly need to contact your local planning department to discuss your ideas with them. You may also need to gain permission from the freeholder and/or management company. If this is the case, it is likley that you will need to apply for planning permission. Similarly, if the building falls within a conservation area, or is listed, you will also need to apply for planning permission.

Regardless of the tenure of the property, the design and build will still need to adhere to Building Regulations and be ‘signed off’ at the end of the works by a third party. When this occurs, a completion certificate will issued at the to confirm the legality of the works (see our Blog ‘Know your Stuff: A Guide to Building Regulations and Planning ). If the correct sign off is not gained, then it can cause problems when selling the property later down the line.

It is also worth bearing in mind that if your home in semi-detached or part of a terrace, then a loft conversion is likely to require you to serve party wall notices on your neighbours in accordance with the Party Wall etc. Act. These notices will be required for any change to the structure of the shared wall, for example the insertion of steel beams in to the party wall or removal of a chimney breast. These additional costs can come in at around £600 - £2,000. See our Blog: Know the Facts: What is a party wall award and how much will it cost?  for further information. We have also included a Blog on how to save money on party wall awards, so check out our top tips here:

Conversion considerations…

It is worth considering a few points before embarking on a project. Here are some of the most notable:

  • Does the current structure provide enough height for the conversion in to a habitable space?

  • Will the roof pitch allow for the conversion?

  • Will the current structure support the conversion?

  • Are there any obstacles in the space that may hinder the development.

  • How will the current layout of the property affect my design?

To take the first point, Building Regulations specify a minimum of 2.2m head height for a space to be considered as ‘useable’. During surveys, we have visited properties that have marketed the loft room as an additional bedroom, only for buyers to pull out as we have highlighted that the roof space is too low to officially be considered as habitable. Such instances show the importance of ensuring all works are compliant with Building Regulations.

With regards to the ceiling height, even if the new space meets the requirements, we highly recommend that you ask your designers to explicitly detail how the space will work in 2D/3D plans. Spend time imagining life inside the space and how it will feel, especially taking into account the pitch of the roof. By realising the space in advance, it will avoid any disappointment down the line. If, when you see the plans, you think it may be unworkable, it is time to discuss with your designers how to gain the extra space you desire. This may include raising the roof on top or lowering the ceilings below.

The roof structure of most houses comprises of trusses or rafters and the type of structure will have implications for the build. In order to tell which type of roof you have, rafters run along the edge of the roof and will leave most of the triangular space below hollow. This makes a conversion easier than trusses, which are supports that run through the cross-section of the loft. If your property has the latter, extra structural support will be required for the conversion of the loft.  

With regards to additional obstacles, your designer will also need to consider the potential relocation of water tanks and/or appropriate removal and support of chimney structures.

Where your new staircase will be positioned will depend on the existing layout of the property and the position should be considered early on in the design process. Building Regulations set out a number of requirements for staircases and these include elements such as minimum stair depths, the height for balustrading, the separation between spindles and the number of steps in a straight line. The most popular placing for a new staircase often is above the existing staircase; this is because the least floor space is ‘lost’ in this arrangement.  That said, we are seeing an increasing amount of more creatively positioned staircases, so this is worth talking through with your design team. Decisions such as placing the door at the top or the foot of the staircase can also drastically change the ‘feel’ of the space.

If you are considering an en-suite in your loft, bear in mind that it will prove most cost effective to position the new bathroom as close as possible to the existing waste and supply pipes. This will make the plumbing simpler and therefore cheaper to install.  Bear in mind that baths take up more space and need to fit up the stairs for installation, although showers will always need to be positioned in an area of full head height (as do hand basins).

Additional thoughts:

Here are some additional thoughts to consider when planning your space:

  • It may be worth bearing in mind that if your property lies beneath a flight path, the new room may be subject to significant noise. If so, talk to your designer about additional soundproofing!

  • Remember that as a general rule, glazing should take up 20% of the roof surface in order to maximise the natural light.

  • Whilst loft conversions typically help to make Victorian homes more energy efficient (due to the improved insulation), you will also need to bear in mind that such spaces can still be prone to becoming warm in summer and cool in winter. This is due to the numbers of external facing walls and the position of the space at the top of property. Because of this, make sure you have talked through the provision of effective insulation and adequate ventilation options with your designer.

  • Adequate ventilation is especially important in any bathrooms that you are considering. Where a window is not possible, ensure that you have made provision for mechanical extraction. As a sideline note, on our travels, we have witnessed many a macerator pump ‘go wrong’ in loft spaces. We would therefore, always recommend, where possible, wastes to be plumbed in to the existing drainage.

  • In order to comply with Building Regulations, you will need to consider fire safety for your new room. This means the provision of egress from the windows, the inclusion of fire rated safety doors and a fire protected escape route from the roof space to an outside door. Sprinkler systems and fire alarms also need to be considered, as do existing first floor ceilings, which will need to achieve 30 minutes fire resistance (so may require additional plaster boarding and plastering). Ensure you have talked through fire safety with your design and build team.

  • Do consider the eaves as usable space… the position of baths and storage solutions in the eaves can maximise what would be otherwise wasted!

  • It may be worth checking if you have bats in your loft space before you start... Bats and their resting places are a protected species and safeguarded from the disruption caused by building works!

It all sounds good… now who can I call?

If all of the above sounds good, you are ready to take your first steps…but who to call? You have a couple of options available and these are outlined below:

  • You may wish to commission a designer (a surveyor, architect or architectural technologist). These professionals can produce drawings suitable for planning purposes and the drawings can also be put out to builders on a competitive tender basis. If you choose this option, please be aware that you will also need to factor in additional fees for a structural engineer.

  • The second option is to employ a design-and-build contractor, who will have a designer, engineer and builders in their team. Whilst they may offer a ‘less creative’ option (when compared to a designer), the advantage is that you will be paying an ‘all-inclusive’ price.

Whatever you decide, ensure that you ask to see examples of previous projects and make sure you get at least three quotes, ideally five, from the teams. It is also worth checking out our Blog: Should you give your Builder a Deposit:

We are pleased to say that we are seeing an increasing amount of loft conversions, and loft pods, being granted by planning departments, so, with the information above, you should be well prepared to embark on creating an exciting space with enviable views of your own…