The link above will re-direct you to Homebuilding & Renovating website for more helpful information (Studio Architecture Ltd is not affiliated with this site)

Cost of Project 

There are a number of variable factors that will affect the project cost. As a very rough guide, cost can be estimated as follows.

Location/ Contractor

Depending on your location and the demand for contractors, the price will be higher if there is a lot of building work going on around you. London is around 10% more expensive than the average cost due to contractor and material costs.

Internal Finishes & Fit out

Internal finishes, can vary greatly, so be aware of the rough cost from the supplier if you have something particular in mind. Kitchens and bathroom also vary hugely in cost, you should factor in the cost for these items separately to the construction

Amount of glazing

If your vision is for a super modern highly glazed extension, you should be aware that this will increase the construction cost significantly compare to standard extensions that integrate with existing building design.

Type of roof on extension

Flat roofs on an extension will generally save you on cost if you are not including large skylights on the flat roof. A large roof light will normally require steelwork as structural support and therefore bring the cost to higher than a pitched roof.

Party Walls

If you are proposing to do work directly to a party wall; for example using the wall to support a steel beam, this will be imposing additional loads to the wall and will require party wall notice to be served by the property owner. You will also need to serve notice if you are excavating within three or six meters of a neighbouring wall or if you are building to the boundary wall.

It is the property owners responsibility to ensure that Party wall notice has been served to the affected neighbours.

The Party Wall Act etc. Act 1996 gives people wanting to do work to their properties specific rights and it also allows the neighbours a say over how the rights are exercised and protects against damage or adverse effects from the proposed works. The party that is proposing to carry out the work must first serve a notice on affected neighbours. If a neighbour consents the works can progress, otherwise that will be in 'dispute' and a Party Wall Award must be made. In both cases the neighbours receive the protection from the Act. We would recommend appointing a party wall surveyor in the event that a Party Wall Award is required.

There is a great deal of free information online and even free notice template letters. Follow the button link here to be redirected to a helpful external website. (Studio Architecture Ltd is not affiliated with this site)

Right to Light

In order to safeguard the natural light amenity to existing properties, planning authorities will enforce the right to light 45° and 25° rules.

In Layman's terms this means that you will not have a planning application approved that does not comply with these rules unless a sun light survey is conducted by a light consultant and it is discovered that their would not be an adverse affect on the right to light of existing neighbouring building though existing apertures (i.e. the centre of windows or glass doors).

Right to light rules are not applicable to permitted development applications.

To understand these rules there are many websites with diagrammatic explanation to understand the rules. Essentially, the rules are very simple. The button below will re-direct you to a helpful external website that explains the rule and how it affects you in more detail. (Studio Architecture Ltd is not affiliated with this site)

The Planning Portal

The Planning Portal website has some helpful interactive mini guides that contain information about planning related subjects. Just click on the parts of the house to access the information. The button below will re-direct you to the planning portal mini guides and interactive house (Studio Architecture Ltd is not affiliated with this site)

Permitted Development Rights

There are certain permitted development rights on houses that do not require a formal planing application and we will be able to advise you if your project falls within these constraints. Permitted development is not applicable to listed building or flats but may be applicable to buildings within a conservation if the Local Authority have have not already removed the permitted development rights to the house or the area. It's worth checking this before applying as you may have an application granted under permitted development rights that would otherwise be refused in a planning application. 

Permitted Development Rights have various classes with separate rules for each class. The most common classes used for householders are as follows;

• Permitted Development Class A – Enlargement, improvement or alteration

• Permitted Development Class B – Additions to the roof

• Permitted Development Class C – Other alterations to the roof

• Permitted Development Class D – Porches

• Permitted Development Class E – Outbuildings

There are many rules for permitted development rights for houses, if you would to view a detailed explanation, click on the link below for the technical guidance official document from the Gov.uk website.  (Studio Architecture Ltd is not affiliated with this site)

Larger Home Extension 

Householders are able to build larger single-storey rear extensions under permitted development rights. The size limits will double from 4 metres to 8 metres for detached houses, and from 3 metres to 6 metres for any other type of house outside Article 2(3) land* and sites of special scientific interest. The applications are made on a Prior Approval notification. We will explain the process to you, however if you would like to read more, the Planning portal website has a more detailed document to explain the process. Click on the link below to be re-directed to this document.

Change of Use

You can apply for change from various commercial use to residential on permitted development rights. This is done on a prior approval notification, but is slightly more complex than other applications. If you would like to know more about this, please send us an enquiry by clicking on the link.