Month: June 2021

Offices

The Regs: Take safety into account when designing partition’s

One of the questions we regularly get asked is whether or not Building Regulations apply to minor works to fit out offices, shops, and so on. In most cases the answer is ‘yes’ and there are quite a few regulations that you can fall foul of if you are not careful.

It will come as a surprise to many that even a simple project to subdivide an office can require building control approval. This is because the regulations apply to any alteration that affects the means of escape in case of fire, even if it there is no structural work proposed. Conversely, taking down partitions to make an open plan office can also require permission, as the partitions may have formed a means-of-escape corridor or other form of protected escape route.

A typical scheme might involve creating a new office or meeting room within an existing open plan layout. This is known as an inner room, and specific rules apply, as the only escape route is through another room and a fire in the outer room could trap someone inside. Therefore, Building Regulations require that:

  • the capacity of the inner room does not exceed 60 people (which could rule out meeting and conference rooms)
  • the escape route from the inner room should not pass through more than one outer room
  • the travel distance from the inner room to the exit(s) from the outer room should be limited (usually to 18m in total)
  • the outer room should not be a place of special fire hazard
  • the outer room should be in the control of the same occupier; and
  • in order to give early warning of a problem, either
  1. the partitions of the inner room should be stopped at least 500mm below the ceiling, or
  2. a vision panel not less than 0.1m2 should be located in the door or walls of the inner room, or
  3. the outer room should be fitted with automatic fire detection which is audible within the inner room.

Other considerations include:

  • changes to the emergency lighting and fire exit signage may be required
  • changes to sprinklers or fire detector locations may be required
  • wall and ceiling linings should be controlled and the surface spread of flame rating limited.

Note that if you are dividing a floor into separate occupancies, the means of escape from each occupancy should not pass through any other occupancy. If the means of escape will then include a common corridor or circulation space, then either it should be a protected corridor or a suitable automatic fire detection system should be installed throughout the whole of the storey.

Therefore plans should always be prepared for building control approval which show the following: proposed uses of each space; fire escape routes; fire compartmentation; cavity barriers to floors and ceilings; fire rating of doors and partitions; proposed ironmongery; fire alarm layouts; exit signage; emergency lighting; and sprinkler layouts (these are often best shown on a reflected ceiling plan).

This article originally appeared in AJ Specification

Clean Air Day

Its Clean Air Day today (17th June 2021) and the Worlds’ focus is on the quality of air that we breathe. Unsurprisingly a lot of attention is being given to outdoor air pollution, with people being asked to reduce emissions by walking, cycling or using electric vehicles. However, less attention is being given to the quality of indoor air in buildings, yet this potentially has a far greater effect on the health of the nation.

Indoor Air Quality (IAQ) is a critical issue given that people living in developed countries can spend as much as 90% of their time indoors. This has been exacerbated by the measures put in place to combat Covid with the most susceptible individuals – such as the elderly and those with pre-existing medical conditions – spending almost all their time inside. Greater provision of Houses in Multiple Occupation (HMO’s) have also seen an increase in this issue with people living in cramped single aspect rooms, and undertaking cooking, living and sleeping functions all within the same multifunction space.
When the energy efficiency standards in Part L of the Building Regulations were strengthened in 2006, 2010 and again in 2013, new buildings were required to be more airtight by reducing heat losses through unwanted gaps and cracks in the fabric. However, by reducing this uncontrolled ‘infiltration’ it means that far more care must be taken with the ‘purpose-provided ventilation’ from devices such as trickle ventilators and fans designed into the building. These are controlled under Part F of the Building Regulations with guidance being contained in Approved Document F (ADF).

There is still clearly a lack of understanding of the health risks associated with IAQ, and its rare that a week goes by where we are not asked by an Architect if they can omit trickle vents because they are not aesthetically pleasing, or a contractor asking if a workplace can omit mechanical ventilation as the client doesn’t want to pay for it.

In 2019 the Ministry for Housing Communities and Local Government (MHCLG) published a study into the quality of air in mew homes. In total, 80 homes had been studied in the period from November 2015 to February 2016, across seven developments within England, and the results were shocking as nearly all homes did not meet the recommended ventilation provisions – some by very significant levels.

Only 2 of the 55 naturally ventilated homes met the guidance in ADF with respect both to trickle ventilator provision and local extract fan air flow rates. Homes with whole house mechanical ventilation systems faired no better with just one of the 25 homes in the study meeting the guidance published in ADF with the cause being that the extract fan flow rates were below those recommended, in some cases by as much as 85% below the recommended flow rate.

These results are especially disappointing given that one of the key changes in the Part F 2010 revision was the introduction of a legal requirement for testing and commissioning of installed fans, and for the installer to notify the building control body of the commissioning and the air flow rates. This is again an area where we see huge resistance from contractors to supply the necessary certification prior to occupation.

There is also currently a lack of awareness amongst the occupiers of buildings, of the vital role that ventilation plays and how and when to operate that ventilation. Nor are people aware that certain activities such as cooking or even using scented candles are polluting the indoor environment. It is likely that if occupants were more aware of this, they would try to keep such activities to a minimum or ensure that appropriate measures (such as purge ventilation) are used as mitigation.

In 2006 ADF sought to introduce a complementary strategy of ‘source control’ by reducing the release of volatile pollutants into the indoor air. Sources include formaldehyde and VOCs from plastic-based building components, fabrics and furnishings. In 2012 the Zero Carbon Hub recommended that such products or components be banned from use indoors and recommended the greater use of natural products with low or zero emission of pollutants.

The Government have responded to these finding and in January of this year published a consultation on revisions to ADF. This included a recognition that Mechanical ventilation has the potential to be the most proficient means of ventilating a modern property, although this provides a conflict with the need to reduce carbon emissions and energy use. The revised guidance proposes an increase the minimum airflow through these systems to each bedroom by 6 l/s. This has been introduced as there are concerns especially in bedrooms overnight when doors are kept shut – this is especially true in HMO type accommodation. The other expected change here is an increase in the background ventilation from 2500 mm2 to 5000 mm2 in extract-only systems.

Its not just new building’s either that need to be addressed, as the overall drive to improve thermal efficiency and the increased demand for home extensions are also having a negative effect on IAQ. For example, simply replacing existing windows is likely to increase the airtightness of the building. If ventilation is not provided via a mechanical extract and supply ventilation system, then increasing the airtightness of the building will reduce useful ventilation in the building. In these circumstances, it should be ensured that the ventilation provision is considered, and additional measures introduced to prevent IAQ reaching unacceptable levels.

Good Luck England

As the Euro’s start today we are sending our support out to the England team and wishing them good luck in the tournament.

As former Wembley Winners ourselves we know just how thrilling it is to come away from the famous stadium with a trophy.

Whilst we cant guarantee Gareth and the boys will have similar success  we can make sure that you have your plans in place for a successful tournament. Thats why we have decided to produce this Euro Wallchart so you can plan when the key games are and when not to book  your concrete pour!