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Basement Conversions – from the Chartered Surveyors view

Home owners, Landlords and Letting agents…Would you like to increase rental yield or the value of your property?

Are you prepared for the 2016 change in energy efficiency and the private rented sector, does your basement comply with Building Regulations?


Basement conversions – Much more than just a luxury!

Logo smallTHINK BASEMENT specialises in basement conversions in the private residential sector, offering amazing transformations to existing underground spaces.

In addition to the aesthetic benefits, converting a basement level will provide significant improvements to the internal environment of the entire house! THINK BASEMENT has partnered with Mike Kidder, Chartered Surveyor, to investigate the impact that a basement conversion can have.

In many houses, unconverted basements are usually cold, damp spaces that could allow moisture and draughts to penetrate other parts of the house and create problems with condensation. Cold air circulating beneath the floorboards of ground floor living spaces will also result in potential heat loss and will reduce the thermal efficiency of the building as a whole.IMG_4508

In the past homeowners have tried to solve these problems by blocking up ventilation grates and redundant coal chutes in the belief that this would help prevent cold air and moisture entering the cellars. In reality this often makes the situation worse by stopping the flow of air and trapping moisture in the sub floor areas, leading to problems with timber decay and expensive repair bills dealing with conditions like Dry Rot.

By tackling damp and poorly vented cellars a number of potentially damaging and harmful issues, such as natural build concentrations of radon gas and timber decay, can be resolved. The British Property Federation recommends maintaining your property in good repair:


‘It is essential that damp and damaged building elements are tackled before or alongside energy efficiency improvements. A damp wall will transmit heat out of the building more readily than a dry wall, and could cause structural problems and health issues for tenants’.

Mike Kidder says: ‘Basement conversions are very useful and beneficial at all of the different levels of treatment from the basic floor replacement and improved ventilation for storage areas, to the full blown tanked and sealed rooms that can be used for additional living rooms. Most people do not realise that these rooms can be converted and consequently they get overlooked, or people think that the costs outweigh the benefits’. In most cases the cellars are the same floor area as a lounge or dining room and could provide a considerable amount of extra space within a terraced house for more beneficial use.

One of the aspects of a condition report undertaken by a chartered surveyor is to assess whether the work that has been undertaken on a basement conversion meets the associated Building Regulations and is classed as safe for habitation.

With the potential in an existing basement to increase a properties living accommodation by up to 50%, and the vast majority of cases requiring no planning permission and offering minimal disruption during the works, many property owners are deciding to investigate how they can turn their basements into the spaces that they need, with the features that they desire.

 ‘I would estimate that in Sheffield and the surrounding areas, only 10-15% of basements have been converted, with around only 2% of these complying with Building Regulations’

– Mike Kidder

THINK BASEMENT has seen an increase in enquiries from Landlords and Letting agents who are looking to increase their rental yield and get a great return on investment by converting their basements into additional residential accommodation. This is often in properties that have no scope to extend the house in any other way, because of site limitations. In the case of rented properties, the potential economic benefits can be significant. Properties in Sheffield, in the S10, S11 and S6 postcodes indicate that a double room in a rented house can command a rental value of between £55.00 to £65.00 per week. An investment of £15,000 to create a double bedroom (most likely with en-suite) at basement level could be recouped within 4 to 6 years.

In addition by converting a basement, the energy efficiency of a property can be upgraded as a parallel benefit. The briefing document regarding the forthcoming change 2016 in regulations entitled ‘Energy Efficiency and the Private Rented Sector’ states that under the Energy Act 2011, the government will be introducing new requirements for every property offering rented accommodation, both private and subsequently commercial, to meet a minimum level of energy performance.

A basement conversion undertaken by THINK BASEMENT will  meet the required Building Regulations regarding habitation, and as a matter of course will include the following measures to address energy performance:028

  • Installation of a water proofed and thermally insulated concrete floor
  • Management of damp and moisture away from the structure of the building
  • Installation of solid wall insulation
  • Insulation of ground floor services, such as central heating and hot water pipes to reduce boiler demand and therefore reduce energy consumption
  • Installation of suspended timber floor (between joist) thermal insulation
  • Installation of active air ventilation systems ensuring removal of any excessively moist air from the internal environment
  • Installation of low energy consumption lighting and water maintenance systems
  • Installation of high-performance double or triple glazed windows and/or doors
  • Option to replace and upgrade existing central heating systems

In addition to the above features in every conversion, THINK BASEMENT are able to offer services that can be applied to any part of the property:Membrane

  • Installation of internal Solid Wall Insulation (InSWI)
  • Installation of External Solid Wall Insulation (ExSWI)
  • Installation of Solid or Suspended floor insulation
  • Installation of damp-proof measures including Direct Injection, Cavity drained membranes and Cementitious (Render-based) waterproofing.

Internal Solid wall insulation can be fitted on a room by room or whole property basis, often undertaken in conjunction with decorative upgrading or refurbishment of bathrooms or kitchens. Internal SWI will generally cost less than External SWI to install, however External SWI is thought to have marginally better thermal insulation properties. A combined system approach to improving energy performance can be taken, ensuring damp in walls is addressed before the installation of thermal insulation, thereby maximising efficiency. The aesthetic impact of External SWI may be a consideration and can be limited by installing only to rear or less visible walls, whilst applying Internal SWI to the front or outwardly visible parts of the property.

epcsAll of the measures above form part of the recommendations that appear on the Energy Performance Certificates (EPCs) that every property must have at the point of sale or rental. The benefits of specifying these features during a basement conversion includes likely low levels of disruption to the rest of the property and the ability for building inspectors and surveyors to work with THINK BASEMENT and record every part of the installation process. The opportunity to incorporate cutting edge technologies and renewable energy sources is tremendous during a THINK BASEMENT project…why not consider installing ground or air source heat pumps, biomass boilers or even take the opportunity to incorporate the infrastructure for solar panels or wind turbines into your property, the basement offers and excellent location for the management systems needed for these systems!

The importance of energy efficiency in the private rented sector is likely to grow over the next few years. New regulation, in particular plans to provide tenants with a right to request energy efficiency improvements from April 2016 and to make it illegal to let energy inefficient property as determined by the EPC from April 2018, are likely to have a significant impact on the sector. However energy efficiency is not just about getting ready for legislation, it can offer Landlords and home owners a fantastic opportunity to upgrade and improve their properties and maximise the value of their investments.

What should you do NOW?mike-kidder

The partnership between Mike Kidder Associates Ltd and THINK BASEMENT provides you with the ability to determine which scheme would be best suited to meet your particular requirements for a basement conversion. A survey will advise on the condition of the existing cellar/basement and recommend what improvements could be undertaken. A valuation could be provided to enable you to see the difference in the Market Value of your property with the works completed, further enabling you to make the correct decision on which type of scheme to opt for. If you think that your basement would benefit from being improved then please use the contact details below:

You can find THINK BASEMENT online: or contact us: or 01142583500.

You can find Mike Kidder Associates online: or contact us: or 01143215081.


Think-Basement-Logo mikekidderassociateslimited-sheffield-0


Relatived Posts
Basement Conversions – from a Structural Engineers View ( 19 Mar,2014 )
Basement Conversions: from the Structural Waterproofing Consultants view ( 23 May,2014 )
Going Underground… ( 8 Jan,2014 )
Basement Conversions: from an Architects view ( 21 Feb,2014 )
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