Vapour barriers


Now that the weather is quickly becoming more comfortable indoors than out, this is a great time to discuss indoor air quality.  We will start with vapour barriers (VB’s).  There are several approaches to vapour barriers; a generation ago there was a huge effort to implement VB’s in homes.  NRC Canada through R-0000 series made it very clear that VB’s were extremely important. Since then much has changed and come to light regarding this integral part of any building envelope.

In the 70’s it was clear that heating and vapour flows in building were integral, and that controlling them was key to a comfortable indoors.  VB’s also helped keep precious heat from escaping.  Today the average track home builder doesn’t really believe in a completely sealed vapour barrier. Many builders feel that VB’s should be installed and that the transition from one floor to the next or from the basement to the ground floor shouldn’t be continuously sealed. For them the building should breathe and that completely sealing a VB’s leads to sick building syndrome or at least a build up of unhealthy air in the home.  Couple continuously sealed vapour barrier with agglomerate based furniture and petroleum derived carpets and the air content in the home becomes overwhelmed with V.O.C.’s.  When your vapour barrier is properly sealed these gases have nowhere to escape and the air in the home can become unhealthy.  Builders usually only include very simple mechanical systems with new homes.  The only line of defence is a home owner that will flush the homes air on a regular basis; unfortunately you cannot rely on individual monitoring of indoor air quality. This is another reason why GC’s don’t seal VB’s properly.

Commercial buildings have the solution to this issue, in them VB’s are permanently sealed, but these buildings have sophisticated mechanical systems that are monitored. This is the solution to a properly sealed VB.  Your mechanical system has to be properly designed and monitored to avoid poor indoor air quality. There are several additional pieces of equipment that are required to properly monitor indoor air quality. First an air exchanger is required with a heat recovery unit.  This will allow the system to change the air in the home and recover the energy stored in the air before flushing it. Second, you need a monitoring system. This has to be designed into your mechanical system and co2 sensors should be placed in every zone to monitor the air quality.  This is included in the latest national building code.

It is recommended that your home be divided into as many zones as possible to allow for proper response to climate requirements. The issue is cost; sophisticated mechanical systems are pricey and can significantly add to the overall cost of the home. The trade off for high upfront equipment cost is reduced energy cost over the life of the system. When you do the math, these systems pay you back in savings not to mention increased comfort and a healthy indoor environment.

If you need a permit we can help call 514-839-3138.

Grandfather clause


j-a-macGrandfather clause is a term used to explain the right a building has related to when it was built.  Our landscape is full of buildings from different eras. The laws applicable at the time of construction change over time so in consequence if you live in an old row house with a non conforming stair; that stair can remain, as dangerous as it is; because it was built in a bye gone era and its ‘grandfathered’.

The building code under its current iteration is transforming itself into an instrument to be interpreted. Since the building code is a series of laws the code itself is now being interpreted as law and can be argued as such.  Jurisprudence is being implemented and it puts the odes on the stamping consultant to interpret their judgment should a dispute arise.

I bring this up to clarify something many folks don’t understand but will become clear.  If you have a grandfather clause building and you undertake a major renovation you in effect lose your grandfather clause and likely will be required to bring your building up to the current code and local bylaws.  It’s simple, if you maintain your building with regular scheduled maintenance you are fine but if you start moving walls and proposing new stairs, you cannot build the new stair like the old. You will have to follow current building codes for design.

This is essentially the reason many folks just leave older buildings for new. It’s simply easier to build from scratch rather than to adapt an old building to new standards. This phenomenon is also known as filtering of the building stock.  Old buildings are usually considered to be filtering down towards the bottom of the housing stock as their designs become obsolete.

At the moment many of Montreal’s inner city boroughs are experiencing a reverse filtering. That is they are being renovated to be resold as condos and they are finding many eager families willing to undertake the expense to convert old buildings to current standards due to the value of a pied a terre en ville.  This type of activity creates tension in boroughs that had a homogeneous population demographically and then all of the sudden has wealthy families inserting themselves into the landscape creating pressure for neighbouring properties to be renovated and low income residence being displaced.

The Montreal metropolitan area is very clear in its promotion of public transit and taxing of Montreal car drivers.  The message is clear; tolls are coming to bridges that access the city; like most US and European cities. We should all use public transit. With this kind of policy Montreal’s dense core is being favoured and predictable consequences are ensuing. Montreal’s inner city is a hot real estate market. Many European and American real-estate businesses are well routed in Montreal’s hot urban scene. There are few economies as potent as Canada’s in the current world economy.

If you need a permit we can help call 514-839-3138.