for a quick no obligation quote call
020 8930 5668 or enquire using the form below

Installing insulation and vapour barriers, particularly in existing buildings not originally designed for them, often leads people to ask whether the building will “sweat” as a result. It’s possible to understand the thought processes that might lead to that question, but is there any truth in the idea?


To put things in some context: the human body produces sweat to help regulate body temperature. The body gets hot, sweats, and the evaporation of that moisture off the skin introduces a cooling effect to help reduce the temperature.

Trapped moisture

It’s a common experience, especially for anyone who enjoys the great outdoors, to put on a plastic (or, more accurately, non-breathable) raincoat and find it becomes wet on the inside within minutes. The body sweats and the evaporated moisture condensates on the inside of the coat.


In building projects, when the specification calls for a vapour control layer – especially a plastic-based one like polythene – perhaps it is this ‘raincoat’ effect that people are thinking of and worrying about. That as the building is used, moisture will form on the vapour barrier.


Condensation isn’t sweat

Building occupants generate moisture through everyday activities: cooking, cleaning, washing, bathing, breathing and – yes – sweating. The moisture vapour is held in the air, but it’s not a result of helping to control the temperature of the building. It is entirely a by-product of people living and working in buildings.


As the temperature of air changes, the quantity of moisture vapour it’s able to hold also changes; the warmer the air the greater its capacity. When warm air comes into contact with cooler surfaces, it drops in temperature and can no longer hold the same quantity of moisture.


If it was already at or close to saturation point then the moisture it can no longer hold is deposited as condensation – such as on a cold beer glass in a warm pub or inside a cold raincoat worn by a warm person.


Cold surfaces in buildings

Anywhere that insulation is missing or badly installed and allows warm air to leak from a building is a potential cold spot – and a potential area for condensation to occur. Windows are also a prime candidate for condensation, since they typically have a worse thermal performance than the surrounding building fabric.

It’s right to be concerned about condensation, because it is unwanted in buildings. It creates a damp and unhealthy environment for a building’s occupants, and can lead to mould growth. If it occurs within the building structure, unseen, and is allowed to accumulate over time, it can also lead to structural failures – for example, if timber elements start to rot.



Buildings might not sweat, but controlling moisture is very much something to think about. It’s understandable that people get concerned about installing vapour barriers and airtight layers. Positioned correctly, however, they can be very effective and help protect the building fabric.


Next month we’ll look at how airtightness, insulation and ventilation work together in modern construction to minimise condensation risk.

SBEM calculations are required by Part L,  of the Building Regulations for England and Wales.

If you are heading up a new build, it is critical that you know about SBEM calculations. As well as how they work, when you need to get them, and how they impact your final construction.

Research has shown that while UK building law is stringent yet clear, many constructions develop issues around gaining compliance. According to the study, this stems directly from a lack of knowledge around requirements.

If a project does not comply with requirements, and cannot be passed by building control, this can lead to costly holdups and alterations to the construction.

No developer or architect wants this.

Therefore, read on to learn everything you need to know about SBEM calculations.

What SBEM Calculations Are For

SBEM stands for Simplified Building Energy Model. It is the approved framework for calculating the energy performance of buildings that are non-domestic. They are the non residential or commercial equivalent of SAP calculations, which estimate the energy performance of residential buildings.

SBEM calculations compute values relating to, building materials used, ventilation systems, HVAC systems, lighting needs, glazing, energy input required for heating and lighting per annum, as well as components such as solar PV systems.

The energy performance of buildings is measured on a scale of 1 – 100, with 100 being zero energy consumption.

SBEM calculations not only work out whether or not a planned construction will pass energy efficiency requirements, but they also act as a framework/ blueprint that informs the different construction phases in order to for the building to meet requirements once it is completed.

SBEM calculations form the basis for generating what is called an EPC (Energy Performance Certificate) which is issued at the end of a build to show whether or not a building has passed all energy efficiency requirements.

What Types of Constructions Require Them

As mentioned above, SBEM calculations are required for all non-domestic buildings.

Here is a list of examples of these types of constructions:

  • Hotels
  • Offices
  • Factories
  • Schools
  • Resturants
  • Retail developments
  • Warehouses
  • Student housing
  • Care homes

Although student housing and care homes could be thought of as dwellings these generally require SBEM calculations.

The rule of thumb is that if units are self-contained, they fall into the catagory of dwellings and require (individual) SAP calculations. Any shared areas or units that do not contain kitchens or bathrooms need SBEM calculations. Constructions that include both self-contained units and shared areas require both SBEM and SAP calculations

There are also two exceptions to SBEM requirements. These are places of worship and non-heated buildings. If you planning construction of these, then it is unlikely that you will need to get SBEM calculations.

As regulation enforcement can vary between regions, it is best to consult your local building control body to ensure that you are getting the right calculations carried out.

Who Carries Out SBEM Calculations

SBEM calculations are conducted by energy and sustainability consultants, such as us. Sustainability consultants compile the required data from your project within the government-approved software to generate the calculations report.

After this, they will advise you, should you seek guidance on energy efficiency related areas of the build. Once construction is completed they will ascertain and prove whether or not the building complies with the SBEM calculations, in order for it to gain its EPC.

Energy consultants are monitored by accreditation authorities to ensure that they conduct these services correctly.

When to Get SBEM Calculations

SBEM calculations are carried out during the pre-construction phase of a build. Ideally, SBEM calculations should be integrated into the design phase. By doing this you will be able to have confidence that your construction will pass the final evaluation.

This also allows for any modifications to be planned in if the projected energy efficiency score needs to be increased. Unfortunately, many developers neglect to get SBEM calculations in the design phases and put it off until the end. This can result in costly problems.

Changing plans is much cheaper and swifter than changing already erected constructions, so we strongly advise that you book your SBEM calculation service as soon as possible.

How They Are Carried Out

In order to carry out accurate SBEM calculations, the energy consultants you are working with will need to have access to as much information about the construction as possible.

This includes but is not limited to:

  • Floor plans
  • Site plans
  • Section
  • Elevations
  • Insulation types used and their thicknesses
  • Specifications of heating and cooling systems
  • Specifications on hot water generation
  • Specifications of ventilation systems
  • specification of the glazing
  • Light specifications and information on lighting controls
  • U-value of openings
  • Specification of renewable technologies and systems
  • Construction accreditation details

Once in possession of the required information, your energy consultant will compile the SBEM calculations. The time this takes is largely dictated by the project’s size/scope.

What to Do With Your SBEM Calculations

Once you are in possession of the SBEM calculations these need to be passed on to your builder and project manager. They will need to utilize the data to ensure that all specifications and u-values are implemented correctly. This will ensure that you project can successfully gain its new building EPC once completed.

Schedule Your SBEM Calculations As Soon As Possible

SBEM calculations are critical for the successful approval of non-domestic construction projects. To guard against common and costly issues that involve redoing sections of work, ensure that you schedule SBEM calculations for as early on in the projects as possible—ideally during the planning phase.

If you are in need of energy efficiency consultants or have any questions, feel free to contact us to discuss your needs. We are an experienced team of energy consultants, dedicated to making your energy efficiency approval process a clear and smooth one.

According to the statistics, the number of homes to be built in London has doubled from that of last year.

If your building project is among these numbers, it is important that you know about sound tests.

According to regulations, sound tests need to be conducted and passed in order for new building projects to be approved by the board of building control. Without certification, your project could come to a grinding halt.

Read on to find out what is a sound test, as well as how to get one conducted and when to arrange one.

What Sound Tests Are

Sound tests are procedures carried out on new buildings and projects to ensure that developments yield adequate levels of noise attenuation performance.

These tests are carried out by independent acoustic consultation parties, such as ourselves. Upon completion of the test, if compliance levels are met, results are submitted to the building board.

If compliance is not met, adjustments and modifications to the insulation of the building in question will need to be carried out to ensure compliance with the minimum noise attenuation requirements as per Part E of the Building Regulations for England and Wales

The Importance of Sound Tests

All new dwellings and residential conversions that create adjoining dwellings require soundproof testing. Without a sound test certificate, the final building will need to be approved and the project can not be legally completed.

How Sound Testing Works

During a sound test, the acoustics team will carry out two types of attenuation tests. These are airborne noise tests and impact noise tests.

Airborne noise generally consists of things like conversation, and television and radio sounds. Impact noise refers to the sound that comes from the impact of footsteps on the floors.

The team will set up sound testing equipment to generate airborne and impact noise and then measure this on the other side of any dividing structure between dwellings such as walls, ceilings, and floors.

The size of the structure will determine how many individual tests need to be carried out. A small to medium-sized construction will generally require roughly 2 impact floor tests, 2 airborne floor tests, and 2 airborne wall tests.

When to Get a Sound Test

Noise tests should be carried out as early as possible during the building phase. If minimum noise attenuation levels are not met during the test, changes can be made to insulation measures with less difficulty and expense that if these were to be carried out after the construction is fully completed.

For example, if modifications need to be made in a fully completed set of housing units, components in kitchen and bathrooms areas will likely need to be removed, as well as carpeting, flooring, and wall panels. This can incur unnecessary and exorbitant costs for a project.

However, at the same time, buildings also cannot be tested too early.

To increase the chances of passing the sound test, the following components of the project need to be completed:

  • Walls, floors, and ceilings (including plastering)
  • Internal doors should be hung
  • Windows and external doors hung and glazed
  • Ventilation systems installed
  • Light switches and electrical plug outlets should be in place
  • Skirting boards should be installed
  • Any gaps in floors or ceilings should be fully sealed

While these elements should be in place, there are also a few things that should only be installed after sound testing has taken place. These are:

  • Cosmetic floor coverings
  • Kitchen units
  • Bathroom units
  • Built-in cupboards and wall units

As you can see, it is quite critical to time your noise test for the optimum stage in construction. Therefore, it is a good idea to book the test well in advance. Once you have booked a test, you can liaise with your acoustic testing service for an exact date closer to the time to ensure that you test at an optimum stage in construction.

How to Get a Sound Test Done

Sound tests are relatively simple processes, however, you will need to prepare the building beforehand for the sound testing team.

In order to gain accurate results, you will need to ensure that the following takes place:

  • Make sure that all windows and doors are sealed
  • Close all ventilation system openings
  • Have all rooms that are to best tested cleaned and tidied (optimally there should not be anything in the rooms)
  • 240v (50Hz) mains power is available in all areas to be tested

Additionally, you also need to make sure that testers can gain access to all rooms. Outside noise should be kept to a minimum so as not to influence test results.

Also, no work can be carried out on the site while the testing is taking place.

Do You Need a Sound Test for Your Building Project?

Soundproof testing is required for the construction of all new dwellings as well as for any construction that modifies a freestanding (previously single) dwelling for multiple living uses. It is also required when converting previously commercial space into dwellings, such as offices into flats.

As well as these types of construction, you might also want to look at sound testing if you are planning proposals for new gyms, restaurants, bars or nightclubs, and industrial and dyno-tuning complexes. These types of establishments all generate heightened levels of noise.

If you need to book a sound test for a project in or around London, do not hesitate to contact us and we can discuss your project timeline. Not only do we offer sound tests, but we are also building regulations Part L specialists, and can assist with a range of test services, for both residential and commercial needs.

If eco-friendliness and environmentally conscious behaviour are your main priorities, you’ll want to invest in the tools that will help you achieve that with your building.

In this regard, you can’t go wrong with a Simplified Building Energy Model (SBEM) report. An SBEM report comes with a series of calculations and measurements that lets you know exactly how your building is making use of energy.

Consider these points to learn more about this report and how it can be useful.

Understand What SBEM Is and What It is For

SBEM refers to a highly intuitive software platform that gives you clear and concrete data on how your building is using energy on a regular basis.

You’ll need to have a professional familiar with this software and the assessment process to conduct the evaluation. During the assessment, the professional will go through the various zones in your building in order to measure how efficiently your home is using energy.

This way, they can find areas where you can make improvements to save money and make your building’s performance optimal.

They will give you clear data on how well your building is heated, insulated, lit, cooled and ventilated. Having this information can dictate every upgrade you make and how you utilize energy.

The Benefits of an SBEM Report

Since you now know exactly what an SBEM report is, it’s vital that you learn exactly why it’s beneficial. Consider these advantages:

1. It Keeps Your Building In Compliance

When you want a building that is compliant with local sustainability planning conditions and building regulations, an SBEM report is a must.

These reports keep your building in compliance with CO2 emissions, the National Calculation Methodology (NCM), and national minimum energy efficiency standards. By making sure that your building is assessed and in compliance, you will reduce your carbon footprint and also lower the likelihood of infractions and fines.

2. You’ll Get Access to Loans and Grants That Can Be Useful

There are plenty of programs in place that you can take part in once you get an SBEM report.

When your commercial building is sustainable, you may also be able to get access to government-sponsored building loans.

When you find the best loans, you will also enjoy a plethora of building cost savings as well. This is useful whenever you are planning a renovation or new construction.

3. Your Building Will Remain Up to Date With Technological and Eco-Friendly Standards

When you adhere to certain eco-friendly standards, your project may qualify for government benefits and other such perks throughout the years.

This helps you to make changes that always keep your home or commercial building modern. Right now, electrical, heating, cooling, lighting and plumbing systems are all moving toward more eco-friendly practices, so you should modernise your home in this way as much as possible.

Doing so will save you more money in the long run, and will also help you to grow the equity of your property.

4. Understanding Your Property’s Energy Performance is Helpful For Design and Upgrades

Today, particularly, you need to be sure that you are incorporating energy-efficient principles into your design.

By having a breakdown of every facet of your commercial building or home’s energy use, you will make design decisions that count. Whether you’re installing new fixtures or renovating different rooms in the building, you can do so with a solid foundation when you have an SBEM report.

You’ll save money on your project because it’ll be completed quicker and with a lower likelihood of mistakes or inaccuracies.

5. Professionals Will Assess Your HVAC System to Help You Get Savings and Better Performance

Your heating and cooling system is the biggest user of energy in your building. When you get an SBEM report, the technicians can determine exactly what kind of heating and cooling repairs will save you money.

These repairs will give your HVAC system better performance as a whole and makes sure that you aren’t wasting energy and resources during wintertime and summertime.

Use SBEM to the Fullest

An SBEM report gets you the data that you need quickly. Since you are getting an assessment from an energy professional, you will be able to take action with any suggestions right away.

Having this data is especially useful when you are trying to take a project to tender.

The water, sunlight and other energy calculations will be useful to you when you need to prove Part L building compliance and furnish proof of energy certificates. Since this report is so useful, you’ll need to make sure that you get the help of the best professionals and store your report for recordkeeping purposes.

Consider These Tips and Get an SBEM Report

By getting an SBEM report, you will enjoy all of these advantages, and then some.

Whether you simply need to demonstrate compliance or want to design a high quality energy performance building, have access to up to date energy data for your own records, getting one of these reports can be just what you are looking for.

Consider these points about getting a report and take the time to reach out if you need our services.

For more help with SBEM calculations and reports, contact us online or give us a call at 020 8930 5668.

From award winning networking to award winning translation.  The foreign language is building regulations part L.  As a quadrilingual individual I have frequently watched people speaking to each other in their own tongue in the vain hope the other will understand. Even speaking loudly doesn’t seem to help.  Their expression of relief, when I’ve helpfully stepped in to assist inspires me to convey essential building sustainability compliance in simple easy-to-understand English or Spanish or Italian or French if required.

A prime example recently came to light. A young developer who has heard me speak at a construction forum contacted us about a new project – their first to confront sustainability compliance. He wanted to understand the process for this new development – a change of use from offices to 5 flats and a new building on the same site with a new block of flats.

We had a meeting, I explained about building regs part L and the essential design stage SAP calculations that establish the best way forward for the heating, glazing and insulation.  We discussed the As built SAP calculations and new dwelling energy performance certificate or EPC for building control sign off.

The project is now underway. I get an email from the client.  He is confused asking me why we told him he needs SAPs when the BCO has just asked for EPCs with no mention of SAPs!?!?  I was confused too until I read the BCO’s letter which talks about L1A, L1B and EPCs.  In fact, he was giving the same information as me but, in another language, building regulations Part L.

When he referred to LIA compliance, he was talking about the SAP calculations with enhanced u – values for the new build residential dwellings.  When he referred to LIB he was in effect requesting SAP calculations for the change of use flats to demonstrate the improved energy performance of the proposed flats within the existing dwelling.

The pièce de résistance of this email was the mention of the EPC. The client understood one thing. The BCO meant something else. In laymen’s terms an EPC is “the thing you get from the estate agents to sell or let the property”. That is how we hear it described.  In a situation where building regulations are involved the EPC is in fact a New Dwelling EPC. It is produced directly from the SAP calculations and therefore reflects far greater construction details giving the best possible rating for a building.

The other EPC is the one that says RdSap Existing Dwelling on the top right-hand corner of the EPC. It is for the sale or let of existing dwellings.

The two EPCs may look the same at first site but any building control officer worth his or her salt will spot the difference immediately and will most certainly not sign off a project with the wrong one.

Having explained all of this to the client he was very relieved (and so was I) that he had, in fact, correctly understood the process.