This is the story of Sava

We are a team of building physicists and engineers, software developers, surveyors and business management specialists and for 40 years we have been Making Buildings Better.

This is the story of Sava, from our inception in 1983 we have had many adventures!

1983 – 1994

1995 – 2000

2001 – 2010

2011 – 2016

2016 – Present

1983 – 1994


  • 1983

    Energy advisory services and energy ratings are born

    Professor Jake Chapman, Professor of Energy Systems at the Open University sets up Energy Advisory Services. Its primary mission is to devise a method for calculating the energy performance of residential properties. This is driven by the need to give householders independent and reliable advice on how to save energy. This same calculation method could then also be used to set standards and drive market demand for energy efficient homes.


  • 1990

    Energy ratings go national

    The UK’s first nationwide, quality assured, energy rating scheme is launched. The National Home Energy Rating (NHER) scheme is a collaboration between Energy Advisory Services and the National Energy Foundation.

    NHER certificates are used by house builders, social landlords, mortgage lenders and homeowners to establish the energy performance of their homes. The NHER has its own rating – a scale of 1 to 10 based on energy cost – to communicate the home’s energy credentials.


  • 1992

    The Government’s SAP rating is devised, a derivative of the NHER rating

    SAP is developed by the Building Research Establishment (BRE) for the former Department of the Environment in 1992, as a tool to help deliver its energy efficiency policies. The SAP methodology is based on the BRE Domestic Energy Model (BREDEM), which was developed between the company and the BRE. The SAP will be used for building regulation compliance from 1995 onwards.

  • 1994

    We’re renamed National Energy Services

    Due to the success of the NHER scheme, the National Energy Foundation becomes a shareholder in the company, and we’re renamed National Energy Services (NES). The NHER has 1,000 organisational members and 3,000 qualified and accredited energy assessors. National Energy Services has 8 different software products that can provide detailed analysis.

    In the photo you can see a young Paul Wolfe – Sava’s Software Director – who is even programming outside!

1995 – 2000


  • 1995

    Helping local authorities meet their statutory obligations

    The Home Energy Conservation Act (HECA) creates new obligations on local authorities to report on energy efficiency improvements. The company launches new products HECA Profiler and HECA Manager to help authorities gather information on the housing in their jurisdiction and provide advice to householders.

  • 1997

    Innovation for housebuilders

    The company launches an innovative guarantee scheme for new build housing. The Energy Cost Guarantee allows housebuilders to offer guaranteed energy bills for new home buyers. The idea failed to take off but it served as a high-profile innovation that helped push forward the need for low-energy housing and low fuel bills for residents.

  • 1998

    Identifying fuel poverty

    The Affordable Warmth Index is launched by the company – a software tool that enables the quantification of fuel poverty in order to present stronger cases for its alleviation. It compares the predicted fuel costs for the property with the actual or predicted disposable household income to derive affordability.

  • 2000

    Providing surveying expertise for Warm Front

    The company partners with energy provider TXU (later known as E.ON) to manage the Warm Front scheme for the East of England. We provide the surveying resource with 60 new team members. Warm Front is a government scheme to help vulnerable households, including those in fuel poverty, to benefit from energy efficiency improvements such as home heating and fabric insulation measures. A total of 2.3 million households received assistance from the Warm Front scheme across England during the Scheme’s life.

2001 – 2010


  • 2001

    New legislation drives more consumer information

    The draft Energy Performance in Buildings Directive is published by the EU. This Directive, along with the Housing Bill for England and Wales in 2003 drives our development activity for the whole decade. The EU Directive mandates the introduction of Energy Performance Certificates (EPCs) whenever any building is constructed, sold or rented out. Whilst the Directives’ deadline for implementation was 2006, it took until 2009 until the requirements were fully implemented.

  • 2002

    We launch the World’s first online energy advice service

    The company develops “e-efficiency”, the world’s first (as far as we know!) online energy advice service for householders. It was first deployed for the energy company E.ON, and subsequently is used by many other energy companies, as well as the Energy Saving Trust. e-efficiency allows householders to quickly model their home using different levels of data to get specific advice on energy cost savings and carbon reduction.

  • 2003

    Beyond energy and into residential surveying

    The company acquires SAVA (Surveyors and Valuers Accreditation Ltd.), a consultancy and training organisation that is helping Government to produce the mandated Home Condition Report as part of the Home Information Pack. SAVA trains individuals for the newly created role of Home Inspectors and becomes the first certification scheme.

  • 2004

    Collaborating to devise the new RdSAP

    The company collaborates with the Building Research Establishment (BRE) and Elmhurst Energy to devise the Reduced Data SAP (RdSAP) methodology, the calculation that would be used to produce EPCs for the UK’s existing homes.

  • 2007

    EPCs finally become law

    EPCs are introduced and the NHER Accreditation Scheme becomes the leading scheme for Domestic and Commercial Energy Assessors.

  • 2010

    Here comes the sun!

    With the introduction of Feed In Tariffs, the company launches SunSwitch, a PV design and installation service. In a forerunner to the Green Deal, SunSwitch would use experienced energy assessors to advise customers on the merits of a PV system.

2011 – 2016

(and then small again)

  • 2010

    The Green Deal

    The new Liberal Democrat / Conservative coalition government get behind the idea of the Green Deal, an all encompassing scheme of finance, installation and guarantees that allow householders to invest in energy saving measures funded through a loan attached to their property.

    The Green Deal is a major focus for several years, with the company contributing resource to develop the necessary Occupancy Assessment calculations and accreditation framework for Green Deal Assessors.

  • 2011

    Acquired by Kingfisher plc

    Seeing the commercial and environmental importance of the Green Deal, Kingfisher plc, Europe’s leading home improvement retailer (who own B&Q and Screwfix), acquire the company. For the next 5 years the focus is establishing the training, software and accreditation framework needed for Green Deal. We also assist Kingfisher in launching their own energy saving propositions.

  • 2013

    We go mobile!

    ‘NES Touch’ is launched – an Android and iOS application for completing EPCs and Green Deal assessments.

  • 2013

    The Energy Company Obligation (ECO)

    The company launches an online Energy Company Obligation (ECO) calculator, used by 300 contractors and consultants working in the ECO supply chain. It’s the first Ofgem approved tool for ECO scores.

    We take on several contracts with Energy Suppliers to meet their ECO obligations and end up installing over 3,000 gas and oil fired boilers in households who meet the “hard to heat” criteria.

  • 2014

    Diploma launched to increase skills in Residential Surveying

    Responding to skills shortages within the residential surveying and valuation sector, the company launched a new Level 6 Diploma, with support from the RICS, ABBE and employers.

  • 2015

    The Green Deal is quietly wound down (i.e. scrapped!)

    With the arrival of a Conservative Government in May 2015 and a continual number of problems within the Green Deal around consumer demand and quality, the Green Deal is scrapped. This creates a watershed moment for the company to take a new direction.

2016 – Present


  • 2016

    Taking back control

    The company undertake a management buyout from Kingfisher plc. Following a strategic review, the core business of EPC training, software and accreditation is sold, leaving the company free to pursue fresh markets.

  • 2016

    Installing boilers for ECO and MK residents

    A new boiler installation service, Optima, is launched which allows the company to deliver its ECO contracts for energy providers using its own resource. Optima is expanded to offer a premium installation service for able to pay customers in and around Milton Keynes.

  • 2018

    National energy services becomes Sava

    After many years of operating two brands for our products – National Energy Services for energy efficiency, and SAVA for residential surveying – we change the company name from National Energy Services to Sava, Along with a new brand identity the company coalesces around the new Sava name and purpose of ‘Making Buildings Better’.

  • 2018

    First ever national careers fair for residential surveyors

    The first National Residential Surveying Careers Fair is held bringing together trainee surveyors and employers.

  • 2019

    Sava Intelligent Energy is launched

    Sava launches its new Sava Intelligent Energy software that provides calculation, analysis and improvement planning for reducing energy and carbon in housing.

  • 2021

    Sava buys BlueBox Partners

    Sava buys the specialist residential surveying training business BlueBox Partners. The acquisition allows Sava to work directly with BlueBox’s expert panel of experienced residential valuers and surveyors that Sava use to deliver training for its diploma programmes. This provides more control of the customer experience as well as enhancing development work into new initiatives.

  • 2022

    Sava strengthens its analytical and strategic support services

    Dr Neil Cutland joins Sava to head up Sava Analytics, a new business unit focussed on providing analytics and strategic support for our customers as they plan for their journey towards zero carbon.

  • 2023

    Sava celebrates 40 years in the industry

    Coming a long way from our inception in 1983, Sava celebrates 40 years supporting the residential property sector through education, technology and professional services, adapting and evolving over the past four decades to meet the needs of the industry.


Energy advisory services and energy ratings are born

Jake worked with the Building Research Establishment (BRE) to devise a calculation model – the BRE’s Domestic Energy Model, that would be used as the basis for energy ratings in the UK.


A benchmarking tool was devised for the Milton Keynes Development Corporation to specify the energy performance of new homes at Energy World, an international exhibition in the new city of Milton Keynes.  The result was the Milton Keynes Energy Cost Index (MKECI). It was a huge hit with architects and builders since it enabled them to work out for themselves which combinations of measures worked best for reducing energy costs. It would be the forerunner to the NHER rating, itself a forerunner to SAP and Energy Performance Certificates.

The company went on to develop a range of software products to allow architects and consultants to model the energy performance and improvement of both new and existing homes.

The MKECI was used to benchmark performance at Energy World, an international exhibition of 50 energy efficient houses in 1986.

Professor Peter "Jake" Chapman
Professor Jake Chapman is pictured circa mid-1990s having just been awarded a Royal Society Gold Medal for contributions to energy efficiency.


Energy ratings go national

The NHER had a virtuous circle providing qualifications, software, technical support and a quality assurance regime. This ensured accurate energy ratings were produced that consumers could trust. The NHER model was used many years later as the basis for the EU Directive on the Energy Performance of Buildings (EPBD) that would introduce EPCs into the UK in the late-2000s.

In the photos below you can see some of the original NHER promotional material as well as Prime Minister Margaret Thatcher looking at our software at the launch of the NHER in 1990.

  • A collection of marketing material used to promote the NHER scheme from the early 1990s.
  • UK Prime Minister Margaret Thatcher, looking at NHER energy software developed by Sava in 1990