There are various factors involved in understanding the cost of a project. These include the scale of the refurbishment, impact on the existing rooms / services, right through to the paint specification. Costs cannot be easily determined as the overall sum will be heavily dictated by the structural alterations and your personal specification requirements.
For a basic breakdown of what you should expect to spend, follow these guidelines: Note that this excludes the kitchen, glazing and floor finishes.
Cost / Budget:
Ground floor extension only, including the internal refurbishment of existing areas directly connected to the proposed extension: £75,000 – £88,000 + VAT
You will have to carefully consider the specification of the internal / external finishes to complete the project within this range. The sum does not include for bespoke items, such as a kitchen, appliances, worktop, glazing, floor finishes and external landscaping. It does however include for standard electrics, plumbing, decoration and other works required to complete the project.
Loft conversion only: £45,000 – £54,000 + VAT.
Note that you will have to carefully consider the specification of the internal / external finishes to complete the project within this range. The sum does not include for bespoke items, such as wardrobes and also the floor finishes. It does however include for standard electrics, plumbing, decoration and all other works ready for use. You may have to consider the upgrading /strengthening of the existing roof, repairing / replacing the finishes, replacing all of the habitable room doors to FD30 and re-pointing of the existing chimney. This should be assessed by your design team and further guidance provided.
Other costs that you will need to consider relate to the internal redesign / reconfiguration. For example the bathroom and rooms that will need to be refurbished as a result of the works. Your plumbing and electrics will also have be assessed carefully to ensure that they are adequate for the development / additional loading. This should be discussed with the contractors when they are invited to tender for the works. Also note that if you decide to complete the extensions in stages, you should look to futureproof the property to minimise abortive works.