How to Successfully Tackle A Loft Conversion? A-Z Guide

dormer lofts

Many things are involved in converting the loft section of your house; a few are complicated, while some can be done in no time. Suppose your house is suitable for conversion. Next, you have to follow several important steps.

First, accurately measure the available space. Next, consider the four main types of loft conversion and select the one that best suits your needs. Finally, choose a competent builder or architect to carry out the project.

However, it’s essential to note that this process doesn’t have to be overly complicated. I’m saying this since my team and I have spent hours collecting the data and making the process easy with the help of this comprehensive guide.

Start With, Is My House Suitable for Conversion?

Before proceeding with a loft conversion, assessing whether your house is suitable for the project is crucial. Here is a guide to help you determine if your house meets the requirements:

Check the Permitted Development (PD) Allowance

In most cases, homes are allowed for permitted development, which allows for loft conversions without planning permission. However, there are restrictions based on the property type:

  • Terraced House – The development should not exceed 40 cubic metres.
  • Semi-Detached House – The development should not exceed 50 cubic metres. Living in a conservation area or having a low roof space might complicate the process.

Assess the Roof Type

By examining your loft hatch, you can determine the type of roof your house has:

  • Rafters – If the roof has rafters running along the edge, it leaves a hollow triangular space below. Converting such a loft is generally easier and less costly.
  • Trusses – If the roof has trusses, which support running through the cross-section of the loft, extra structural support will be required to replace them. This can increase the cost of the conversion.

Measure the Head Height

The lowest head height needed for a loft conversion is 2.2 metres. You can measure this yourself by using a tape measure to determine the distance from the floor to the ceiling at the tallest part of the room.

Remember that older houses, especially Victorian ones, may have lower ceilings and might not meet the necessary head height. Consider any potential obstacles like water tanks or chimney stacks when planning the conversion.

Consider the Staircase

The staircase is a crucial element in loft conversions, and it’s important to factor it into your plans. Assess the optimal location for the staircase and calculate the required space for its installation.

Keep in mind that even a thoughtfully designed, space-efficient staircase can occupy a considerable portion of a room. Ensure that you have sufficient space available and carefully consider its impact on the overall flow and functionality of your home.

Additionally, the staircase should be able to accommodate furniture when moving it to the loft. Customised staircases can be considerably more expensive than standard ones.

Ensure Compliance with Building Regulations

Check the relevant building regulations and planning permission guidelines to understand the requirements you need to comply with. To ensure a safe and compliant loft conversion, such as headroom, staircase location, step height, and fire safety measures must be considered.

Look for Similar Conversions in Your Area

To get an idea of the feasibility of your loft conversion, observe whether any similar properties around you have undergone loft conversions. If you find examples, it is more likely that your house can be converted.

Consider requesting the loft space of neighbours who have already completed conversions. This will help you gauge the size of the space, generate ideas for layout options, and assess factors like lighting and views through skylights.

Choose a Reliable Builder for Your Project

Suppose you’re sure your house suits the loft conversion project. In such a case, you should start by tiring your builder for the project before doing anything else. To hire a reliable builder for your loft conversion project, follow these steps:

Seek Recommendations

Ask for suggestions from family, friends, and neighbours who have undergone a conversion project. Their personal experiences can deliver helpful insights into reliable companies.

Conduct Initial Chats

Have initial conversations with at least three firms to count their suitableness for your project. During these discussions, get a sense of their professionalism, expertise, and pricing.

Request Examples of Previous Work

Ask each company and any builders or architects you’re working with to show you examples of their previous work. Reputable companies will happily provide photographs and may even arrange visits to completed conversions. This permits you to evaluate the grade of their workmanship.

Customer Testimonials

Inquire if you can speak to previous customers of the firms you are assuming. Ideally, aim to speak with multiple customers to ensure a balanced perspective and reduce the chance of the firm selectively providing positive references. Hearing about their experiences first-hand will help you gauge customer satisfaction.

Background Checks

Conduct online searches to uncover any reviews or feedback about the companies you are interested in. This can provide additional insights into their reputation and reliability. If you come across any concerns, address them by discussing your findings with the company directly.

Determine the Suitable Type of Loft Conversions

When deciding on the ideal loft conversion for your needs, three key factors come into play:

  1. Roof Type – The type of roof in your house will impact the most suitable conversion option.
  2. Intended Use – Consider how you plan to utilise the loft space once converted.
  3. Budget – Your available budget will also influence the choice of conversion.

Typically, three types of loft conversions are internal, dormer, and loft conversions that need complete removal and build. Remember, each has sub-types; read this section thoroughly to choose one that suits you.

Internal Loft Conversions

As the name suggests, this type of conversion involves maximising the existing space within the loft without making significant changes to the roof’s structure. It is a cost-effective option that works well when creating additional rooms, such as bedrooms, offices, or playrooms.

The following are the types of internal loft conversions.


Conversion Type




Roof Lights

Add windows, insulation, and floor strengthening to the existing roof slope

– Cost-effective

– Limited additional space


Dormer Loft Conversions

A dormer loft conversion expands the existing roof vertically to create additional headroom and floor space. This type of conversion is suitable for adding extra space and functionality, especially in scenarios where the existing loft area has limited headroom.

The following are the types of dormer loft conversion.

Conversion Type




Single Dormer

Addition of dormer windows to increase space and add symmetry, suitable for conservation areas

– Favoured by planners in conservation areas

– Limited additional space

Side Dormer

Addition of dormer windows to increase head houses’ height with a hipped roof

– Increases head height for specific roof types

– Limited to houses with hipped roofs


Replacement of hip roofs with gable walls to make additional space with full headroom

– Adds extra space with full headroom

– Requires alteration of roof structure

Full-Width Dormer

Provides maximum space and unique loft layout

– Maximises available space

– Requires sufficient roof space for construction

L-Shape Dormer

Suitable for specific properties like Victorian houses with rear additions

– Delivers a significant amount of additional space

– Limited to specific prop

Roof Conversions Requiring Removal and Rebuild

Unlike the internal and dormer loft conversions, this conversion option involves removing the existing roof structure and rebuilding it to create a new space. It provides the ultimate flexibility in terms of design and layout possibilities. However, this type of conversion tends to be the most time-consuming and costly.

The following are different types of these loft conversions.


Conversion Type




Mansard Conversions

Replacing one or both slopes of the roof with steep sides and a flat roof

– Makes adequate volume for an additional storey

– Requires planning permission

Prefabricated Loft

Replacement of the existing roof structure with larger prefabricated trusses

– Quick assembly process

– Temporary inconvenience during construction

Check & Obtain the Necessary Permissions

Check Permitted Development Rights

Determine if your loft conversion falls within the permitted development rights. Typically, you can extend your roof space to 50m3 (or 40m3 for terraced housing) without planning permission.

However, ensure that the allowance hasn’t been previously used up or removed. Strict limits must be followed, such as no additions beyond the existing roof slope and using similar materials.

If your conversion exceeds the permitted space allowance, is in a conservation area, or falls under designated zones, you will need full planning consent.

Seek Professional Guidance

You can also consult with experts who can help you navigate the planning permission process and provide guidance on permitted development rights. Kickstart a consultation to receive assistance tailored to your specific project.

Building Regulations Approval

Loft conversions necessitate compliance with Building Regulations, regardless of whether planning permission is required. It is advisable to pursue a full plans application approach, where you obtain approval for a comprehensive scheme prior to engaging a builder.

This reduces risks and allows the builder to provide a fixed quotation based on the approved design. Building Control officers will review the undergoing work at many stages, and upon completion, they will issue a completion certificate. Hold off on settling the final accounts until you receive this certificate.

Notify Neighbours

If your house is semi-detached or terraced, it is crucial to notify your neighbours about your loft conversion plans. This requirement falls under the Party Wall Act 1996, which ensures that neighbouring properties are informed, and any potential impact is addressed.

Prioritise Safety

As of April 2015, homeowners are accountable for safety on their home projects, regardless of the project’s size. Develop a health and safety plan for your loft conversion and manage it accordingly to ensure a safe working environment.

The Typical Construction Process

The exact construction process for a loft conversion project can vary depending on the conversion type, budget, design, clients’ needs, etc. However, the following are the general steps involved in every loft conversion.

Roof Work

The first step is to work on the roof. This may involve removing existing tiles or slates, installing new rafters, and adding insulation. If you are adding a dormer window, this will also be accomplished during this step.

Building Walls

Once the roof is complete, the next step is to build the walls. This is usually done using timber framing, but brick or blockwork can also be used. The walls will need to be insulated to ensure that the loft is warm in winter and cool in summer.

Constructing Flooring

The floor is usually made of timber joists, with insulation and floorboards on top. If you add a kitchen or bathroom, the floor must be waterproofed.

Installing Windows and Doors

The windows and doors will be installed once the walls are complete. It is important to choose energy-efficient windows, as this will help to keep the loft warm in winter and cool in summer.

Inaugurating Staircase

The staircase is usually the last thing to be installed. It is necessary to pick a staircase that is safe and easy to use.

Finishing touches

Once the construction is done, the loft will need to be finished. This includes painting the walls, installing flooring, and adding insulation. You can also add a bathroom, kitchen, or bedroom feature.

The Cost of a Loft Conversion

I have added a few tables for the different costs of a loft conversion project. You can check the tables and get an estimate for the cost you may need to complete it.

Note: These costs are based on historical data from August 2015 and may vary depending on factors such as location, the complexity of the project, and current market conditions.

It is always recommended to obtain detailed quotes from professionals and contractors for accurate cost estimates specific to your loft conversion project.

Loft Conversion Guide Price per Square Metre

Loft Conversion Type

Price Range per Square Metre (£)

Loft Conversion Type

Simple Rooflight Conversion

£1,200 to £1,500

Simple Rooflight Conversion

Dormer Conversion

£1,680 to £2,400

Dormer Conversion

Note: Prices exclude VAT and fees.

Professional Fees for Your Loft Conversion

Professional Service

Fee Range (£)

Architect’s Fees

£1,200 to £2,400 for planning drawings

Building Regulations Fees

Under 40m2: £385,

For 40 to 60m2: £460

Engineer’s Structural Design Fees

£600 to £1,800

Planning and Certificate of Lawful Development Fees

Planning Application: £172,

Certificate of Lawful Development: £86

Building Control Fees

£960 to £1,200

Party Wall Arrangement Fees

Budget approximately £850 per neighbour


Party Wall Arrangement Fees  Budget approximately £850 per neighbour

Loft Conversion Building Works

Building Work

Price Range (£)


Radiators: £30 per m2,

Underfloor Heating: £45 per m2


£1,800 to £3,500


£4,500 to £11,000


£77.00 per square metre for plastering or dry lining and paint


£24.00 per square metre upwards


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