House Renovation Cost Calculator

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large sliding doorsTV in bespoke wall unitfitting a new kitchen - the joiner levels up the units

A house renovation cost calculator will help people to budget for their home refurbishment. Over the past 15 years we have collected real cost data from our projects and share this with you below.

pricing spreadsheet to calculate building costs

Before we let you loose on the data, we offer a few paragraphs to explain how we control cost, and the steps we take for a successful property renovation. It would be easy to look at the figures below and take them at face value; the important thing is that they are based on a strict specification, and we spend a lot of time getting this right.  You should do the same.

house renovation cost calculator

First, you need time to design, specify, plan, contract, control and monitor.  In 15 years we have never exceeded a client’s budget because of the attention we pay to these elements.  Our page on interior design and house renovation services gives more details.

home cinema equipment

house renovation design and specification

The key to keeping cost under control is to prepare thoroughly – you need a clear and unambiguous design and specification. Drawings are only part of the story; you also need a written specification for everything else, including floor preparation, paint finishes, underfloor heating, lighting and electrics. You also need a separate document listing the additional supply items (kitchen, flooring, bathroom suite). This then gives you the total cost. You can read more about this in our article entitled Controlling the cost of house renovation.

Brexit and Interior Design

planning applications and building control

Make sure you obtain the necessary approval for your project to avoid unwanted surprises and costs later on. We prepare and submit planning applications, and oversee Party Wall agreements, whilst a structural engineer produces building control and construction drawings. In a recent project, we also had to secure a no objections letter from the water authority by showing that construction was more than 3m from a public sewer that ran beneath our client’s garden.

Planning applications Bath and BANES

Contracting for house renovation

For more extensive and expensive renovations we run a competitive tender, taking time to see a contractor’s previous work, obtain references and clarify responses. You can read more about choosing and working with contractors in our separate article.

During a recent tender we used our experience to negotiate a saving of 15-20% for our clients (exceeding £17000). This, in itself, more than paid for our project management fee! You should consider engaging the right specialist at the right time; it can actually save money.

Having agreed a fixed price for the defined scope of work, the next step is to formalise this in a contract. We usually use an off-the-shelf JCT minor works contract, which covers everything you should need.

Galvanised Beam

Renovating the house

Then the work begins. Because you have taken the trouble to specify your detailed requirements, there will be little wriggle room for price increases. One or two elements may be expressed as prime cost (PC) sums or provisional sums, because more information is needed (awaiting the result of exploratory work for example). However, these prices will be fixed once the additional information becomes available. A wise client will have set aside a sensible risk provision (commonly referred to as a contingency), so there should be no big surprise.

By monitoring progress and checking quality as you go, you will achieve your renovation for the stated price. You can read more on how to achieve success in our property renovation guide.

open plan design

House renovation cost calculator

This is the bit you’ve probably been waiting for. The figures in the links below are for guidance only, but should give you a reasonable budgetary estimate to get started.

The costs are from our renovations carried out in the Bath-Bristol area, which is moderately affluent. Typically, you can add 5-10% for projects in London and the South East; for the rest of the UK, you may find prices around 5% lower on average.

For older projects, we uplifted their values to January 2016 economic conditions; this assumed an average annual inflation rate of 3.5%. However, with uncertainty surrounding Brexit and the reduction in the value of Sterling, prices since the referendum have risen by approximately 15-20% per annum on some construction and supply costs. You will need to take this into account when estimating values at current economic conditions, until more certainty returns.

We hope you find this informative. We’ve carried out many house renovations over the years. If you feel that we can help with yours, please get in touch on 07711 857670 or use the contact form on this website.

Best wishes for a successful project.

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