Posts Tagged ‘Insulation’

Why aren’t we all enjoying a quiet night’s sleep?

31/07/2012

The introduction of Building Regulations Part E in July 2003 represented a big step by which all residential developments in England and Wales had to undergo pre-completion acoustic tests and meet certain airborne and impact sound performance figures. In 2004, building to Robust Details was added to this, providing an alternative method to pre-completion testing to show compliance with the Part E of the Building Regulations. So – nine years on, is everything as quiet as a mouse?

Patrick Dent, AMIOA MEng and Technical Director of Total Vibration Solutions Ltd, explores the issue of noise.

Image by Romana Klee on Flickr

Have these regulations meant that all new build dwellings and those formed from a material change of use are being constructed in a way that provides no noise issues and leaves each and every resident as happy as the proverbial Larry? Well, the simple answer is no. My weeks rarely go by without speaking to an individual who is having noise issues within their newly constructed apartment or house, yet when we investigate their complaint we find that the development met the requirements of Approved Document Part E of the Building Regulations.

So what’s going wrong? Do we need to revise Part E of the building regs? Are we overlooking certain things in the testing? Or do the regulations simply not give a result that the end client deems acceptable?

In truth, there are a wide variety of reasons why we are still encountering noise problems. One factor that caused a great deal of issues originally – although a lot of developers and specifiers are now aware of this trait of certain materials – was the problem of creep. Acoustic underlays and under-screed materials, which offered good acoustic performance initially, would continue to deflect under load over time and not recover to their original thickness. This would result in the resilience in the floor being lost, floors dropping, and floors that met the pre-completion testing initially, suddenly failing six months later.

This is quite an easily rectified problem that can be overcome by developers and specifiers ensuring that they do not use materials that are susceptible to creep. Foams are particularly prone to creep, so any foams used in this capacity should be closed-cell and cross-linked, however any reputable manufacturer or supplier should have test data available on the creep performance of their materials.

The more complex problems come when we investigate noise complaints where there clearly is a noise problem, and yet the development still passes the impact and airborne tests required to comply with Part E of the Building Regulations.

One such example I was made aware of recently involved some luxury apartments where the occupants had got together and complained that the sound insulation in the floors of their apartments were not good enough. An acoustic consultant was called in to independently test the floors. The results gave on average an airborne DnT,w+Ctr of 50dB (Part E requires a minimum of 45dB for new builds and 43dB for dwellings formed by material change of use, which the apartments actually were in this case) and an impact figure LnT,w of 52dB (Part E requires a maximum of 62dB for new builds and 64dB for material change of use). In other words, figures that any developers would be very happy with, and that were comfortably within the requirements of the building regulations.

However, what the acoustician did notice was the incredibly low background noise level. So although the noise levels caused by people walking above wouldn’t be noticed within a building with a more “normal” level of background noise, in these luxury flats, such dramatic but inconstant changes in noise level makes the sound very audible and quite disturbing.

A lack of background noise makes occasional sounds all the more noticeable

This brings us to the fact that an individual’s threshold of hearing and their perception of noise will change depending upon the environment that they are in. Part E of the Building Regulations doesn’t take the background noise level into account – so in this case, the occupants of these luxury flats are left feeling aggrieved at what they perceive as poor sound insulation in their building, whilst the builders would point to the testing that shows they have more than exceeded the requirements. So who is at fault?

Problems with background noise levels aren’t the only issues that we see on a regular basis. There is a widely accepted agreement that the tapping machine used in ISO 140 does not provide an accurate reproduction of the noise produced by footfall. Similarly, the test does not consider the low frequency performance and given that what you are hearing – particularly in dwellings formed by material change of use with timber floors – is caused by the deflection of the joists induced by the footfall, which produces sound at much lower frequencies than 100Hz, the ISO 140 calculation methods ignore it.

AcoustiCORK™ agglomerated cork underlay for impact noise and thermal insulation

So does this mean that the tests are useless and we should completely overturn them? Well, the simple answer is no. In the majority of cases, Part E provides a very good standard to ensure that the end occupant is not disturbed by noise. But here is where we need to be careful. It is a standard. It is the minimum requirements that a building needs to achieve. Certain circumstances, such as a low background noise level, a higher degree of luxury etc., will dictate that the builder needs to achieve a far greater level of sound insulation.

You wouldn’t fit out the furniture of a student hall of residence in the same way you would million pound apartments. Neither should you treat the sound insulation in the same way.

Case study: soundproofing a music room using folding sliding doors

09/07/2012

Doors, by nature, will allow a certain amount of noise to escape. However, there are specialist designs and techniques available to help alleviate the level of audible sound. Here is how Baca Architects and Sunfold Systems solved a musical soundproofing dilemma.

The clients wanted the music room to have an open, airy feel

A client approached Baca Architects, requesting that as part of their home they wanted a music room. This room was to form an important element of their living and leisure time.

A central point of the house was perfect for their requirements for entertaining guests and a key part of the family’s time together, but when it came to the times where privacy was required, they needed to be able to close the doors for recording purposes.

To create the open feel the clients required whilst also having the option to shut off the music area, lead architect Robert Barker wanted to incorporate interior folding sliding doors as an effective and visually appealing solution to the overall project. “Noise transfers so easily through most doors, so it was important for the internal folding sliding doors we used to be flawless, to create a balanced sound level,” he commented.

The music room had to be soundproofed for recording purposes

Robert chose to use Sunfold Systems’ timber range of folding sliding doors, the SFK69 painted in white. This is the highest specification timber system available, and is manufactured from triple laminated solid timber sections. As noise control was key, it was vital that the joints, tracks, frame construction and head detail connectors had no air gaps, to make sure that there was no flanking sound either side.

By using slim-width panels and through the natural slim sightlines of the SFK69, both the structure and the appearance of the internal sliding door system worked well together to achieve the desired effect.

Soundproofing sliding folding doors

Green covers from Down Under: an Australian designer’s summary of green roofs

05/03/2012

Our ‘Australian Correspondent’, Mark Iscaro of First Angle, is in the process of specifying a green roof for a client’s building. In this guest post, he takes a closer look at the concept, components and benefits of living roofs.

San Francisco Academy of Sciences, by Osbornb on Flickr

“This blog will be focusing on a new Green Building initiative in Australia that is slowly making its way into the mainstream. Currently a growing trend around the world, the idea of having a green roof is gradually catching on. Even one of my own clients has finally given in and allowed me to put a green roof on their new building in Marysville.

So what is a green roof?

A green roof is a partially or completely covered roof containing a growing medium and vegetation. These are positioned over a waterproofing membrane and can include water retention, drainage and irrigation systems. There are two main forms of green roofing available in Australia: intensive and extensive, the difference being as follows:

  1. Intensive roofs (roof gardens) contain over 300mm of plant growth and can include a wide variety of shrubs, grasses, tree species and even kitchen herbs. They are also more akin to a park or garden, with easy access for recreational purposes.
  2. Extensive roofs contain less than 300mm of growing media, and so are generally lighter in weight. They are suitable for harsher growing conditions and require minimal irrigation, using hardy, low-growing plant and ground-cover species. These roofs can handle slopes up to 30°. Extensive roofs are usually only accessed for maintenance.

Commercial green roof installation, by Arlington County on Flickr

What are the benefits of green roofs?
• Reduce heating (by adding mass and thermal resistance value).
• Reduce cooling loads on a building by 50 to 90% (by evaporative cooling), especially if it is glassed in so as to act as a terrarium and passive solar heat reservoir: a concentration of green roofs in an urban area can even reduce the city’s average temperatures during the summer.
• Reduce stormwater run-off.
• Natural habitat creation, promoting biodiversity.
• Filter pollutants and carbon dioxide out of the air, which helps lower rates of diseases like asthma.
• Filter pollutants and heavy metals out of rainwater.
• Help to insulate a building for sound: the soil serves to block lower frequencies and the plants block higher frequencies.
• Increase agricultural space.

So now that you know a bit more about these wonderful creations and the benefits they provide, why not look at one for either your current home or perhaps your next project?

Note: Information was gathered from Wikipedia & Green Roof Technologies.”

Mark is active on Twitter, and details of his projects can be found on the First Angle design and planning website.

For more facts and figures on green roofs in the Southern hemisphere, Green Roofs Australasia is worth a visit. A good variety of extensive, intensive, semi-intensive and brown/biodiverse roofs can also be compared over at ESI.info. If you are looking to plant a facade rather than a roof, have a look at what’s available in terms of living walls and vertical gardens.

PassivHaus: the devil is in the detail

07/10/2011

The PassivHaus concept is quite a simple one: create an airtight, super-insulated structure, install mechanical ventilation with heat recovery, address thermal bridging, and find yourself with a building that can essentially be heated by a hairdryer. However, as with most things, the devil is in the detail…

Here, I take a look at the following questions:

What does a PassivHaus look like?

PassivHaus is really a design and build process, as opposed to a particular style of architecture. Whilst we may have preconceived ideas of a PassivHaus-certified building’s aesthetics, it could (at least in theory) look pretty much like anything – especially given that existing buildings can be retrofitted to PassivHaus standard.

100 Princedale Rd, Paul Davis + Partners

This was done at 100 Princedale Road – a Victorian house in a London conservation area – by Paul Davis + Partners and contractor Philip Proffit of Ryder Strategies Europe Ltd. This house was the first of its kind in the UK to achieve PassivHaus accreditation, meeting its target to reduce carbon emissions by 80%. (Granted, with the subject of the retrofit starting out as a drafty, four-story old house, there was plenty of scope for improvement.) In other words, a passive house can be anything from a large, new office building to a centuries-old, traditional house. Below are some examples:

Single-family residence in Brooklyn, NYC | Gregory Duncan

Eurogate Sozialbau, Vienna – Europe’s largest PassivHaus settlement? | Tiger46 on Flickr

Passive house office building in Austria | Tõnu Mauring

What does a PassivHaus cost?

The Footprint article on the Princedale Road Retrofit for the Future project includes an interesting breakdown of the cost / payback time / bills before and after completion, making a comparison between refurbishing to PassivHaus or Decent Homes criteria. The Green Building Store, in conjunction with Building magazine, has also provided a breakdown of costs for the Denby Dale PassivHaus in West Yorkshire.

What about air quality?

The more passive (or other enclosed, airtight and sealed) houses we construct, the more important it is that we keep monitoring and assessing the quality of the air circulated in these buildings. Are we avoiding moisture build-up? Is the air too dry? Is there enough of it? Will we see a concentration of emissions inside these buildings, over time, from the building materials used? What are the potential positive/negative effects on occupants’ health and well-being? Housebuilder’s Bible author Mark Brinkley experiments with air quality and CO2 levels in this House 2.0 blog post, relating his findings to PassivHaus standards.

To ensure a good level of fresh air supply, most passive houses are ventilated and heated by mechanical ventilation with heat recovery (MVHR). Heat from the warm air that is being extracted is passed to the incoming fresh air through a heat exchanger – with the result that heat loss is minimised and heating costs are reduced. Ducting is an integral part of this: “Marion Baeli, the architect on the [Princedale Road] project, stressed that in a retrofit with MVHR, the coordination of ductwork requires considerable design attention, and should be integrated right from the start.” (Footprint)

Airflex Pro suspended ceiling ductwork installation (Airflow Developments on ESI.info)

Which products are used in a PassivHaus?

The PassivHaus Institut provides a list of certified building components, products and systems suitable for use in PassivHaus construction. Presumably, as this concept gains popularity and awareness, the list will grow. We have already looked at ventilation. Other important components are energy-efficient windows, airtight seals and thermal insulation.

But of course, a component is only as good as its installation. As well as architects who know how to design a successful PassivHaus, and manufacturers who can make products suitable for this type of construction, we need contractors with the right skills and experience. (PassiveHouse Builders, Passivhaus/LCC, Passive Development and Viking House are some of the firms I have come across.)

Project Green Home, Palo Alto | Mark Hogan

What is it like to live in a PassivHaus?

Bill Butcher, the construction manager of the Denby Dale house, kept a 17-instalment diary during the building process. But what happens post-occupancy? How does the building perform, and how does it shape the lives and behaviours of its occupants? In a separate post, I have taken a closer look at the realities of living in a passive house.

What is the next big thing after PassivHaus?

In the absence of a unified, international environmental standard for buildings, there is a certain amount of ‘competition’ between the different accreditations. There is no shortage of acronyms to choose from, and there are almost as many opinions on which accreditation makes the most sense as there are design-and-build professionals. (For a sensible take on PassivHaus vs the Code for Sustainable Homes, see “The Bout of the Decade” by Sustainable Homes.)

Andrew Holt heads the practice Architectopia in Norway, and also runs a course on sustainable architecture. He has worked extensively on PassivHaus developments. In an Arkitektnytt.no article, he talks about what the next big thing after PassivHaus might be. Mentioning BREEAM, zero-emission housing and “plus houses”, Andrew emphasises the importance of tailoring the standard to the individual project, using different tools to come up with a package that is fit for purpose. He comes to a refreshing conclusion (my translation):

What follows ‘after’ the PassivHaus standard should be a variety of different possibilities, so that our ambitions are based increasingly on the individual project and its local climate and conditions. This would facilitate greater innovation, creativity and cross-disciplinary co-operation. This approach demands a high level of competence within the project team.

An understanding of what the PassivHaus standard is, is a prerequisite for high-quality construction within the energy-efficiency sector. An understanding of what the PassivHaus standard isn’t, is a prerequisite for moving forwards.

PassivHaus office in Langenhart | Train.bird on Flickr

The realities of living in a PassivHaus

07/02/2011

Thermal image of a PassiveHouse (Young Germany)

Once the scaffolding is down and the blower door test has been passed, what is it actually like to live in a PassivHaus? How does it feel to occupy a house that is kept warm using only your own body heat; a house that is completely airtight and needs no conventional heating system? How does it change your behaviour, needs and habits?

PassiveHouse as a concept

The concept of the passive house (or PassivHaus for the internationalists amongst us) is becoming increasingly well known amongst British architects, contractors, developers and clients. It has moved from being yet another forward-thinking construction method that is adopted in mainland Europe but largely ignored in this country, to being championed by a number of UK built environment professionals.

Information abounds when it comes to PassivHaus certification requirements, test results, design detailing, building physics and heat capacities. The Passipedia website is a good resource in this respect. It also gives an interesting historical review of  passive houses from the past. Did you know, for example, that Fridtjof Nansen’s 1883 polar exploration ship Fram functioned like a PassivHaus? Nansen wrote:

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More than two ways to skin a building: smart facades

01/04/2010

tanakawho on Flickr

How does an architect approach the design of a brand new building? What are the primary considerations – function, form, structure, materials, setting, sustainability?

Each designer will have their own priorities, but to the public – outsiders, neighbours and visitors – a building’s cladding forms a large part of our first impression. The cladding is the building’s face, and we often take it at face value.

Increasingly, though, new technologies are allowing a building’s skin to have functions beyond weatherproofing and decoration.

Smart skin: translucent insulation

Impression of a SmartSkin zero-energy building

Dutch architects and engineers Jon Kristinsson and Andy Dobbelsteen have released details on a new smart skin system for zero-energy buildings, conceived by Dr Noor van Andel and Mr Peter T Oei. Tests on prototypes have shown promising results.

‘Smart skin’ is a new concept: a thin translucent skin for buildings instead of walls. Groundwater is used to buffer the temperature difference between night and day and even between summer and winter. Most often, technicians think that energy losses can only be reduced by using thick insulation, or at least high-performance insulation. ‘Smart skin’ is a typical Dutch idea from a wet country with an averagely mild climate and high groundwater level. ‘Smart skin’ is not a well-insulated wall, but uses the thermal mass of groundwater for heating or cooling.

A PDF outlining the project can be downloaded here.

Smart skin: building-integrated wireless access

In another project, Ji Hoon Jeona, Woonbong Hwang, Hyun-Chul Park and Wee-Sang Park have researched the buckling loads of smart-skin composite panels, in this case for use with wireless LAN systems. Here, thin-strip antennas are incorporated into laminate cladding for building-integrated wi-fi access.

Smart skin: biomimicry

MRA's Kepos eco-hotel

An Ecofriend blog post brings details of MRA‘s Kepos eco-hotel. Designed by John Naranjo, the hotel absorbs solar and wind energy through an open skin. The double-skin building facade is meant to replicate a forest canopy:

The technical and sustainable attributes that are being reinforced by the biomimicry concept include learning from the life-supporting aspects of our living environment, obtaining energy, recycling and reclaiming resources and materials. The main component that will be applied to the building’s exterior canopy will be a special layer developed by SMIT called GROW. This canopy incorporates a combination of photovoltaic and piezoelectric technologies in one system that will absorb both solar and wind energy in one open skin.

Smart skin: carbon absorption

In a previous post, we have glanced at how living algae facades can be used to absorb CO2 from the atmosphere. We have also (in our very first, tentative and terribly short blog post) looked at the emergence of living walls.

Smart skin: this is just the beginning

Through nanotechnology, biomimicry, photovoltaic energy generation, dynamic facade technology, membrane development and a growing emphasis on ‘intelligent’ building materials, building facades will increasingly have to work harder, becoming more than just a pretty face.

Cladding images, specification details and case studies can be found on ESI.info:

What does PassivHaus mean?

09/10/2009

passivhaus resources passivhaus products

Mark Siddall of Devereux Architects explains how simple the PassivHaus concept is and why it ‘is arguably THE low energy, low carbon design standard’.

BRE provides a simple comparison between the outline specification of the PassivHaus standard and UK new-build common practice. Notice the wide gap.

ESI references:

Copenhagen Climate Conference

21/09/2009
Can the COP 15 delegates reach a CO2 agreement?

Can the COP 15 delegates reach a CO2 agreement?

On the 7th of December, heads of state, advisors, officials, campaigners and media personnel from over 200 countries are gathering in Copenhagen for ‘COP 15’ – the UN’s historic climate change conference.

The aim of the conference is to hammer out an agreement on how to reduce global CO2 emissions.

This is the most complicated deal the world has ever tried to put together,” says Tom Burke, visiting professor at Imperial College and an adviser on climate change to the Foreign Office.

The 'tck tck tck' site asks for a global wake-up call

The ‘tck tck tck‘ website counts down the days, hours and seconds till the Copenhagen conference, providing campaign updates and climate change news from around the world.

ESI information on products that can help reduce CO2 emissions: