Converting A House Into Two Flats: Costs And Planning Guide
Converting A House Into 2 Flats
More and more homeowners are converting their homes into flats. And it is quite apparent why – the ever-growing demand for flats in London. More homeowners now realise that splitting their property into units helps them increase rental income and increase property value. So how do you convert your house into flats and what are the expected costs? The following guide should help you in this regard.
Steph Fanizza, Architectural Design & Team Manager
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In short, no. It is important to understand that not all sites are suitable for flat conversions. You should research the neighbourhood, are there flats in the area?, look into the transport links, garden amenity and any existing parking. These quick searches should form the basis of your study and quickly tell you if this is a good site or not.
Market research
Finance is also important. If you are thinking of converting your home into flats, make sure that you have conducted a market research to determine the demand for flats in your area.
Many estate agents in the area have information on the selling and renting so you can determine the income to be gained.
Planning Guide
If a house has to be divided into multiple units, it will be required to obtain planning permission.
It is important to assess your properties history, If it is a listed building, you will need listed building consent. If the building is in a conservation area and the conversion involves demolition, it will be required to apply for planning permission for relevant demolition.
Whether you are a homeowner or developer it boils down to how many units can be achieved in a practical and efficient way. Many of our developer clients hope to maximise their site by including only studio flats and 1 beds but councils often have their own priorities and requirements.
Councils seek to retain family sized units, typically 3 beds or more where possible. So to convert your property there are minimum area thresholds to abide by.
Firstly, ensure the property’s original area (ie.not including extensions) is no smaller than 120 sqm, some councils like Wandsworth have raised this to 150sqm, so be sure to double check!
Ealing flat conversion pre-planning drawing 2024
In many cases when converting a dwelling house into a flats it is important to retain a family sized unit (3 bed), often this would result in lesser units. However, it is possible to extend your property to ensure you maximise the number or size of these units.
Table 1 – Minimum gross internal floor areas and storage (m2)
Knowing how many units can be gained can be a tedious process and require some thought into the minimum space standards. Planners often refer to the Technical housing standards – nationally described space standard Published 27 March 2015, table 1 noted below. This document provides the minimum space standard requirements per unit and over the number of storeys. This is the baseline which most councils follow, however, some councils do have their own requirements for space standards so it is worthwhile confirming this.
When developing plans it is useful to consider the below:
Space requirements per flat including built in storage.
Designing a layout which is both appropriate for planning purposes but also appealing to your target renters.
Self- contained access to private flats and amenity space where possible.
Determine if parking is a requirement or if you could go car-free.
Allow space for refuse and cycle storage
Specialists reports may be required
Planning Guide
If a house has to be divided into multiple units, it will be required to obtain planning permission.
If it is a listed building, you may need listed building consent. Make sure to contact the local planning authority before starting work.
If the building is in a conservation area and the conversion involves demolition, it will be required to apply for planning permission for relevant demolition.
Building or Flats Regulations
When a property is converted, it is required to get approval under the Building Regulations.The converted property is required to comply with the current standards and will take into consideration the acoustic implications, accessibility, firesaftey and the overall quality of the construction.
Redevelopment and flat conversion of site in Ealing
Structural drawings are needed for any significant alterations to the built fabric where the building regulation drawings seek to demonstrate the converted units are designed in accordance with building regulations. When carrying out this phase of construction it is recommended to seek advice from your Architect or Principle Contractor on the process of these.
The cost of converting a house into flats depends on the property. There are many factors which can affect the cost implications of converting your property into flats for example; Size of the property, condition of the house, the number of units ..to name a few.
It can involve installing central heating, walls, and bathrooms. When it comes to budgeting for the conversion, its recommended to consider the following fees:
Planning approval from your local planning authority
Approval for building regulation
Finance for development
Installation of new utility meters (electricity, water, and gas)
New heating systems and boilers
New bathrooms and kitchens
Sound deadening/tests
Constuction of private entrances
Staircase alterations
When budgeting it would If the existing building is sound and the existing bathroom and kitchen can be used, you should expect the cost of conversion to be in the range of £1,500 – £2,000 per sqm. The cost of further decoration and detailing can be additional.
Such a conversion project can be considered to be a major and complex development project. Whilst its scale can vary, you should expect it to take up to 6-12 months to be completed.
There are many ways to approach your flat conversion and we recommend reaching out to experienced architects or planners to understand your site potential.
Get professional help
It is best to seek professional guidance when applying for planning permsion. Extension Architecture have experience with the planning process for residential developments, extensions, flat conversions and new build projects. We know what the planners are looking for – from qualitative principles to the minimum space standards for conversions. From the surrounding areas, neighbours, and amenities, everything can be addressed to ensure that your project gets approval.
Eugene Kim, Founder and Managing Director of Extension Architecture, has led the firm for over 14 years, consistently delivering quality solutions. His dedication has been key to the company's growth and success.
