# Retrofit London > Retrofit assessment, coordination, design and testing across London ## Posts - [PAS 2035 explained for homeowners and landlords](https://retrofitlondon.co.uk/guides/pas-2035-explained/): What PAS 2035:2023 is, when it applies, the roles and stages it defines, what changed in the 2023 edition, and what it means for your project. - [Condensation risk analysis explained: surface vs interstitial](https://retrofitlondon.co.uk/guides/condensation-risk-analysis-surface-interstitial/): The difference between surface and interstitial condensation, the methods used to assess each (fRsi, BS EN ISO 13788, BS EN 15026), and which you need for a retrofit. - [Do I need a retrofit coordinator?](https://retrofitlondon.co.uk/guides/do-i-need-a-retrofit-coordinator/): When a retrofit coordinator is required, when it is optional but worthwhile, what the role does, and what to ask before you appoint one. - [Air tightness tests for homes: results, preparation and cost factors](https://retrofitlondon.co.uk/guides/air-tightness-test-homes-results-cost/): What an air tightness test measures, what counts as a good result for a new or existing home, how to prepare, and what affects the cost. - [Damp and mould after insulation: causes and prevention](https://retrofitlondon.co.uk/guides/damp-and-mould-after-insulation/): Why damp and mould sometimes appear after energy improvements, how to tell condensation from other damp, the ventilation rules, and what Awaab’s Law means for landlords. - [Heat pumps in London homes: planning, grants and sizing](https://retrofitlondon.co.uk/guides/heat-pumps-london-homes/): The current permitted development rules for air source heat pumps in England, the Boiler Upgrade Scheme, and why a proper heat loss calculation matters. - [Retrofitting a leasehold flat in London: consents and who decides](https://retrofitlondon.co.uk/guides/retrofitting-a-leasehold-flat-london/): What leaseholders need to check before insulating, replacing windows or changing heating in a London flat – the lease, freeholder consent, planning and building safety rules. - [Internal or external wall insulation? A guide for London homes](https://retrofitlondon.co.uk/guides/internal-vs-external-wall-insulation-london/): How internal and external wall insulation compare for solid-walled London homes – planning permission, Building Regulations, moisture risk and fire safety. - [Understanding fRsi and surface condensation risk](https://retrofitlondon.co.uk/guides/understanding-frsi-surface-condensation-risk/): What the temperature factor fRsi measures, how it is calculated, the critical values in BRE IP 1/06, and what it does not tell you about moisture. - [Heat loss versus heat demand calculations](https://retrofitlondon.co.uk/guides/heat-loss-vs-heat-demand/): Heat loss (kW) and heat demand (kWh) answer different questions. This guide explains each, how they are calculated and when you need them. - [Airtightness and ventilation: how they relate](https://retrofitlondon.co.uk/guides/airtightness-and-ventilation/): Why reducing air leakage and providing good ventilation go together, how airtightness is measured, and what happens when one is improved without the other. - [Planning a retrofit for a London period property](https://retrofitlondon.co.uk/guides/planning-a-retrofit-london-period-property/): How to approach energy improvements in a Georgian, Victorian or Edwardian London home – solid walls, timber floors, sash windows, conservation areas and leasehold flats. - [Retrofit assessor, coordinator and designer: roles explained](https://retrofitlondon.co.uk/guides/retrofit-roles-explained/): Who does what in a retrofit project – the assessor, coordinator, designer, installer and evaluator – and why keeping the roles distinct matters. - [What happens during a retrofit assessment?](https://retrofitlondon.co.uk/guides/what-happens-during-a-retrofit-assessment/): A step-by-step explanation of a retrofit assessment: what the assessor records, how long to allow, what you should prepare and what you receive afterwards. ## Pages - [Website Terms of Use](https://retrofitlondon.co.uk/website-terms/): Terms that apply to using this website. Terms for our services are provided separately with each quotation. - [Complaints – How to Raise a Concern](https://retrofitlondon.co.uk/complaints/): How to tell us if something has gone wrong, what we will do, and where else you can go for help. - [Cookie Policy](https://retrofitlondon.co.uk/cookie-policy/): Which cookies and similar technologies this website uses, why, and how to change your choice. - [Enquiry Received](https://retrofitlondon.co.uk/enquiry-received/): We have received your details and will reply by email or phone. If your enquiry is urgent, call 07506 892739. - [Request a Quote](https://retrofitlondon.co.uk/request-a-quote/): Tell us about the property and what you need. We will reply to confirm scope and next steps. - [Contact](https://retrofitlondon.co.uk/contact/): Call, email or send an enquiry. We cover all of London. - [About](https://retrofitlondon.co.uk/about/): Retrofit London is the retrofit service of PRIMELINKS SOLUTIONS LTD – independent assessment, coordination, design and building-physics services. - [Guides](https://retrofitlondon.co.uk/guides/) - [Privacy Policy](https://retrofitlondon.co.uk/privacy-policy/): How Retrofit London collects, uses and protects personal information submitted through this website and in connection with enquiries. - [Waltham Forest](https://retrofitlondon.co.uk/areas/waltham-forest/): Retrofit assessment, coordination, design, testing and calculations for homes in Waltham Forest, with notes on local housing types and what to check before planning works. - [Sutton](https://retrofitlondon.co.uk/areas/sutton/): Retrofit assessment, coordination, design, testing and calculations for homes in Sutton, with notes on local housing types and what to check before planning works. - [Richmond upon Thames](https://retrofitlondon.co.uk/areas/richmond-upon-thames/): Retrofit assessment, coordination, design, testing and calculations for homes in Richmond upon Thames, with notes on local housing types and what to check before planning works. - [Redbridge](https://retrofitlondon.co.uk/areas/redbridge/): Retrofit assessment, coordination, design, testing and calculations for homes in Redbridge, with notes on local housing types and what to check before planning works. - [Newham](https://retrofitlondon.co.uk/areas/newham/): Retrofit assessment, coordination, design, testing and calculations for homes in Newham, with notes on local housing types and what to check before planning works. - [Merton](https://retrofitlondon.co.uk/areas/merton/): Retrofit assessment, coordination, design, testing and calculations for homes in Merton, with notes on local housing types and what to check before planning works. - [Westminster](https://retrofitlondon.co.uk/areas/westminster/): Retrofit assessment, coordination, design, testing and calculations for homes in Westminster, with notes on local housing types and what to check before planning works. - [Wandsworth](https://retrofitlondon.co.uk/areas/wandsworth/): Retrofit assessment, coordination, design, testing and calculations for homes in Wandsworth, with notes on local housing types and what to check before planning works. - [Tower Hamlets](https://retrofitlondon.co.uk/areas/tower-hamlets/): Retrofit assessment, coordination, design, testing and calculations for homes in Tower Hamlets, with notes on local housing types and what to check before planning works. - [Southwark](https://retrofitlondon.co.uk/areas/southwark/): Retrofit assessment, coordination, design, testing and calculations for homes in Southwark, with notes on local housing types and what to check before planning works. - [Kingston upon Thames](https://retrofitlondon.co.uk/areas/kingston-upon-thames/): Retrofit assessment, coordination, design, testing and calculations for homes in Kingston upon Thames, with notes on local housing types and what to check before planning works. - [Hounslow](https://retrofitlondon.co.uk/areas/hounslow/): Retrofit assessment, coordination, design, testing and calculations for homes in Hounslow, with notes on local housing types and what to check before planning works. - [Hillingdon](https://retrofitlondon.co.uk/areas/hillingdon/): Retrofit assessment, coordination, design, testing and calculations for homes in Hillingdon, with notes on local housing types and what to check before planning works. - [Havering](https://retrofitlondon.co.uk/areas/havering/): Retrofit assessment, coordination, design, testing and calculations for homes in Havering, with notes on local housing types and what to check before planning works. - [Harrow](https://retrofitlondon.co.uk/areas/harrow/): Retrofit assessment, coordination, design, testing and calculations for homes in Harrow, with notes on local housing types and what to check before planning works. - [Lewisham](https://retrofitlondon.co.uk/areas/lewisham/): Retrofit assessment, coordination, design, testing and calculations for homes in Lewisham, with notes on local housing types and what to check before planning works. - [Lambeth](https://retrofitlondon.co.uk/areas/lambeth/): Retrofit assessment, coordination, design, testing and calculations for homes in Lambeth, with notes on local housing types and what to check before planning works. - [Kensington and Chelsea](https://retrofitlondon.co.uk/areas/kensington-and-chelsea/): Retrofit assessment, coordination, design, testing and calculations for homes in Kensington and Chelsea, with notes on local housing types and what to check before planning works. - [Islington](https://retrofitlondon.co.uk/areas/islington/): Retrofit assessment, coordination, design, testing and calculations for homes in Islington, with notes on local housing types and what to check before planning works. - [Haringey](https://retrofitlondon.co.uk/areas/haringey/): Retrofit assessment, coordination, design, testing and calculations for homes in Haringey, with notes on local housing types and what to check before planning works. - [Greenwich](https://retrofitlondon.co.uk/areas/greenwich/): Retrofit assessment, coordination, design, testing and calculations for homes in Greenwich, with notes on local housing types and what to check before planning works. - [Enfield](https://retrofitlondon.co.uk/areas/enfield/): Retrofit assessment, coordination, design, testing and calculations for homes in Enfield, with notes on local housing types and what to check before planning works. - [Ealing](https://retrofitlondon.co.uk/areas/ealing/): Retrofit assessment, coordination, design, testing and calculations for homes in Ealing, with notes on local housing types and what to check before planning works. - [Croydon](https://retrofitlondon.co.uk/areas/croydon/): Retrofit assessment, coordination, design, testing and calculations for homes in Croydon, with notes on local housing types and what to check before planning works. - [Bromley](https://retrofitlondon.co.uk/areas/bromley/): Retrofit assessment, coordination, design, testing and calculations for homes in Bromley, with notes on local housing types and what to check before planning works. - [Brent](https://retrofitlondon.co.uk/areas/brent/): Retrofit assessment, coordination, design, testing and calculations for homes in Brent, with notes on local housing types and what to check before planning works. - [Bexley](https://retrofitlondon.co.uk/areas/bexley/): Retrofit assessment, coordination, design, testing and calculations for homes in Bexley, with notes on local housing types and what to check before planning works. - [Hammersmith and Fulham](https://retrofitlondon.co.uk/areas/hammersmith-and-fulham/): Retrofit assessment, coordination, design, testing and calculations for homes in Hammersmith and Fulham, with notes on local housing types and what to check before planning works. - [Hackney](https://retrofitlondon.co.uk/areas/hackney/): Retrofit assessment, coordination, design, testing and calculations for homes in Hackney, with notes on local housing types and what to check before planning works. - [City of London](https://retrofitlondon.co.uk/areas/city-of-london/): Retrofit assessment, coordination, design, testing and calculations for homes in City of London, with notes on local housing types and what to check before planning works. - [Camden](https://retrofitlondon.co.uk/areas/camden/): Retrofit assessment, coordination, design, testing and calculations for homes in Camden, with notes on local housing types and what to check before planning works. - [Barnet](https://retrofitlondon.co.uk/areas/barnet/): Retrofit assessment, coordination, design, testing and calculations for homes in Barnet, with notes on local housing types and what to check before planning works. - [Barking and Dagenham](https://retrofitlondon.co.uk/areas/barking-and-dagenham/): Retrofit assessment, coordination, design, testing and calculations for homes in Barking and Dagenham, with notes on local housing types and what to check before planning works. - [Areas We Cover](https://retrofitlondon.co.uk/areas/): Retrofit services across all 32 London boroughs and the City of London. - [Who We Help](https://retrofitlondon.co.uk/who-we-help/): Retrofit services for homeowners, landlords, housing providers, architects and contractors across London. - [Heat Loss and Heat Demand Calculations](https://retrofitlondon.co.uk/services/heat-loss-heat-demand-calculations/): A heat loss calculation works out how much heat each room loses on a cold day, in kilowatts, using BS EN 12831-1. - [Condensation Risk Analysis and fRsi Calculations](https://retrofitlondon.co.uk/services/frsi-condensation-risk-calculations/): A condensation risk analysis checks whether moisture is likely to condense in or on a building element. - [Airtightness Testing](https://retrofitlondon.co.uk/services/airtightness-testing/): An air tightness test measures how much air leaks through a building by using a calibrated fan to pressurise it, usually to 50 pascals. - [Retrofit Design](https://retrofitlondon.co.uk/services/retrofit-design/): Retrofit design turns an improvement plan into specifications and details that installers can price and build, including junctions, airtightness and ventilation. - [Retrofit Coordination](https://retrofitlondon.co.uk/services/retrofit-coordination/): A retrofit coordinator manages a retrofit project from assessment to evaluation, evaluating options, preparing a medium-term improvement plan and managing technical risk. - [Retrofit Assessment](https://retrofitlondon.co.uk/services/retrofit-assessment/): A retrofit assessment is an on-site survey of a home’s construction, condition, heating, ventilation and occupancy, carried out by a retrofit assessor. - [Services](https://retrofitlondon.co.uk/services/): Retrofit assessment, coordination and design, airtightness testing, and building-physics calculations for London homes – each with a clear scope. - [Home](https://retrofitlondon.co.uk/): Plan energy improvements on evidence. 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