Basem*nt and Cellar Conversion Specialists in S40 (2024)

FAQs

How much does converting basem*nt cost? ›

On average though, your typical new basem*nt conversion in the UK capital costs around £140,000. That works out at around £1,600 per square metre. If you're having to excavate and underpin a new basem*nt area then a typical basem*nt conversion will come in at around £2,800 per square metre.

For example, converting an already existing cellar is going to be significantly cheaper and easier than excavating a basem*nt from scratch. While enjoying the newly created space may be a secondary benefit to adding value to your home, it's important to remember that there is a 'ceiling value' to most properties.

Converting a simple single-room cellar using a waterproof membrane cavity system (more on this later) can take just two or three weeks, including digging out the sump and fitting the pumping system. However, converting and extending the cellar, including lowering the flooring, can take several months.

As a general rule of thumb, it is thought a fully functional, modernised and usable cellar can add between 10% and 20% to the value of your home.

Adding a bathroom to your basem*nt can increase the value of your home by up to 20% or more! If you're looking to increase the value of your home, adding a bathroom to your basem*nt is a great place to start.

Converting a crawl space to a basem*nt will likely cost $47,500–$135,000 while digging out a new basem*nt can cost as much as $150,000.

Converting an existing residential cellar or basem*nt into a living space is in most cases unlikely to require planning permission as long as it is not a separate unit or unless the usage is significantly changed or a light well is added, which alters the external appearance of the property.

The word cellar applies to the whole underground level or to any large underground room. A subcellar or subbasem*nt is a level that lies below the basem*nt or cellar.

The key difference between basem*nts and cellars is the purpose of each. For instance, basem*nts can be finished off to act as living spaces, whilst cellars are designed to be storage spaces. As a rule of thumb, windows will only be found in basem*nts. If a cellar does contain a window, it will be very small.

The most effective way of tanking your basem*nt or cellar is with tanking slurry. You may sometimes see this referred to as cementitious tanking. Both names refer to the same product - a specially formulated mixture designed to be applied to cellar walls to stop water ingress.

Does a cellar need ventilation? ›

The Importance of Ventilation

It is important to note that a waterproofing system alone can only achieve a Grade 2 environment as to achieve a Grade 3 environment control of the level of relative humidity in the air of the cellar or basem*nt is required (in order to reduce the risk of dampness caused by condensation).

Yes. Finishing a basem*nt is a job best left to the professionals. Because there is so much labor involved, and so many different types of work (dry-walling, electrical, flooring, painting, etc.), unless you are a trained professional, this is not a job we recommend you DIY.

The cost of a basem*nt conversion will increase with every square metre. On average, you can spend anywhere from £800 up to £4,000 for each square metre, dependent on the existing space and your basem*nt conversion needs.

Bedroom: Adding a basem*nt bedroom can cost as little as $3,000 to $12,000 according to HomeGuide, but meeting egress, ventilation and lighting requirements will up the cost.

Finishing a basem*nt can be a good investment. According to cost versus value surveys conducted annually by Remodeling magazine, nationally, the average return on investment for a basem*nt project is around 75 cents on the dollar, and about 86% of the total cost spent in the renovation when it's time to sell.

Overall, while there are potential challenges to digging out a partial basem*nt, it can be a worthwhile investment for homeowners looking to add extra space and value to their homes.

Homeowners in the Pacific region, which includes California, Hawaii, Washington, Oregon and Alaska, are likely to see the biggest ROI on a basem*nt remodel at 86.4 percent. In this region, the average basem*nt remodel cost is $84,062, and the resale return is $72,664.

Converting an existing residential cellar or basem*nt into a living space is in most cases unlikely to require planning permission as long as it is not a separate unit or unless the usage is significantly changed or a light well is added, which alters the external appearance of the property.