Double Storey Extensions

A Double Storey extension designed by a good architectural designer adds space to the ground and first floor of your house whether it’s on the rear or the side. The ground floor can have all the benefits of a single storey extension but no options for roof glazing. The first floor then adds bedrooms, bathrooms, En-suites etc.

CK Architectural York - Double Storey Extensions
CK Architectural York - Double Storey Extensions
CK Architectural York - Double Storey Extensions

DESIGN CONSIDERATIONS

These large and visible extensions need are a lot thought, as the additional spaces will be the same on both floors. Making the first-floor bedroom bigger might create unneeded space on the ground floor, then you must make the roof work.
Bedrooms need to have light, ventilation and means of escape. With two stories, the planning limitations must be considered as the size and scale means it has to be designed to fit with its environment. The regulations are stricter specifically about fire escape and structure. You need to decide what you want to gain from the build, what you are willing sacrifice and how much you should spend. Site checks should be carried out on shared boundaries, party wall, mains sewers and is it a listed building or in a conservation area.

DESIGN OPTIONS

Once you know the room sizes required how to access and ventilate them, you then need to make the external work with the existing house. There are limitations in the planning guide for two storey extensions as they have more impact their surroundings. We like to work with and enhance existing areas where possible as this means less new building, cost and impact. A double side extension will need to look subservient to the house, typically this is done by pulling the front wall back. Clear glazing will generally not be permitted at first floor level within 7meters of a boundary due to overlooking. Getting a good balance is important as if the need for bedroom is driving the extension, you will have to make good use of the ground floor. Double rear extensions should consider the overshadowing and loss of amenity/outlook form the neighbours if near the boundary.

CK Architectural York - Double Storey Extensions
CK Architectural York - Double Storey Extensions
CK Architectural York - Double Storey Extensions

Double storey extension generally need planning permission as the permitted development rights only permit small sizes. There are a lot of things to consider before submitting a planning application. How it impacts the street scene, does it enhance character, does it have negative effect on the neighbours, does it affect light/privacy/amenity. These are the things the planning officer will be checking whilst making their decision.
Our design consultants will give you the best advice on how to achieve your requirements with the best chance of securing planning approval. We will prepare and submit he application on your behalf, then act as your agent talking directly with the council throughout the application.

You will need a building certificate from a building control body, either local authority or private building inspector. We advise gaining the planning permission before paying for the detailed building regulations drawings. Given the additional complexity of the meeting the building regulations for a two-storey extension it is essential that your get the plans approved prior to commencing. These building regulations drawings will then be submitted for a full plan check, amended if necessary and once approved they will be the standard that is built to and inspection against. Our plans will include all the necessary detail such as structure, passage of sound, disabled access, drainage, resistance to moisture, collision, impact, heat loss, ventilation, light, emergency escape and much more. These drawings will have used when the building control officer inspects the build to ensure the builder is carrying out the works correctly. You can commence works 5 days from submitting to building control, this is the minimum time due to having to consult the water authority.

Double storey extension design, planning and building regs in York
Double storey extension design, planning and building regs in York
Double storey extension design, planning and building regs in York

BUILDING AND BUILDERS

Remember when you finally do come to build only half of the building works will be outside, you should plan and phase exclusion zones with your builder. With the approved drawings you can now approach builders to provide quotation and price. Check that any quotation you consider will be written up clearly and with good detail. You will need to know exactly what is priced for and any additional costs should unforeseen issues arise. We have extensive construction knowledge along to assist you and builder throughout. Use our drawings in line with the quotation and any additional information we don’t provide such as plumbing and electrics is agreed in detail before the first fix goes in. it will be costly changing thing once the initial preparation has been built. Our help and advice doesn’t end once you have the approved plans, we will help you throughout the construction process and visit site if required.