Design Advisory Board

Edward Pais was recently appointed by the City Council in Burlington, Vermont to serve on their Design Advisory Board.

"The Design Advisory Board has the responsibility of advising the City's Development Review Board on matters regarding urban design and site planning for proposed development projects reviewed under the City's zoning ordinance."

Preservation Burlington Home Tour

The Preservation Burlington 2010 Home Tour will be held on Saturday, June 26th from Noon to 4 PM.  This years tour will focus on mid-century modern homes.  For more information and tickets, please go to Preservation Burlington's Website.

My residence will be on this year's tour.  It was one of two homes designed by the architect Parker Hirtle and was built in 1957.  The house embodies many of the principles espoused by Frank Lloyd Wright in his Usonian Style.  You can read an article on this home and see some photographs from when the house was first constructed on VermontModern.com.

Rain Water Harvesting

Rain water harvesting can be an excellent source of water for potable, interior gray water, and irrigation uses.  A common interior gray water use is water for flushing toilets.  Rain water harvesting reduces the amount of potable water required from municipal systems and wells, as well as, reducing the amount of storm water runoff, making this an excellent component of any sustainable design.

Collecting water for household uses will typically require multistage filtration and purification, pumps, and backflow preventers, and these systems generally should be designed and installed by licensed professionals. The Texas Commission on Environmental Quality has produced the following guide on Harvesting, Storing, and Treating Rainwater for Domestic Indoor Use.

Rain barrels are an easy way to collect rainwater for irrigation purposes and can often be installed by home owners in a couple of hours.  When full, the water stored in a barrel will often weigh over a quarter of a ton.  For this reason, it is extremely important when installing a rain barrel to place it on a level and stable surface.  While water pressure can be increased by elevating the barrel, this is generally not recommended for two reasons.  First, it is typically not possible to raise it enough to create significant water pressure from gravity as only 0.43PSI is gained from each additional foot.  Second, the risk of serious injury or death is increased by an elevated rain barrel.


Rain barrels and connectors for downspouts are sold at most home improvement stores and garden centers.  Alternatively, rain barrels are not difficult to construct.  A pdf guide for creating one is available for free download from Texas A&M enter L5188 in the Publication Number box and then click on Submit.

On a recent project in Vermont, a rain barrel was added to an existing house in Vermont.  After calculating the amount of rainwater that could be collected and the amount that could be stored, it was determined that the storage could not keep up with the amount that would be collected.  During the winter in cold climates, such as Vermont, rain barrels should be removed and stored.  It was desired that when the rain barrel was full and during the winter when the barrel was in storage, that the existing downspout and drainage system would be used.  The design was based on a basic first flush diverter with a ball valve that could control the flow of water.

"Leaves, insect bodies, animal feces, pollen, pesticides, and other airborne residues collect on the roof.  The first flow of rain washes those elements off.  A first flush diverter collects the first flow of water and allows for the subsequent cleaner water to be directed into the cistern.  These diverters are typically only used for domestic water systems, as the first flow is generally of acceptable quality for landscape irrigation."

The first flush diverter, in this instance, is not acceptable for a potable water system for two reasons.  First, the amount that it collects is insufficient for the roof size and slope.  Second, the diverter needs to work automatically without human intervention.

This system was created by cutting out a section of the existing downspout and replacing it with PVC piping.  The water flows down until it is stopped by the lower ball valve (the red know visible in the photo above right).  The first flow of water collects in the vertical piping.  The subsequent cleaner water flows through the horizontal pipe into the rain barrel.  After the rain, the ball valve can be opened and closed flushing out the first flow of water. When the rain barrel is full or during the winter when it is in storage, the ball valve position can be reversed.  The ball valve is open, allowing the water to flow into the existing drainage system.  For schematics illustrating the adapters and piping used, you you may email me at info@paisarchitects.com.

Geothermal Heat Pumps

Geothermal Heat Pumps are an energy efficient means of heating and cooling a home and can also be used for hot water.  They work with both hydronic and forced air systems.  Forced air systems provide for both heating and cooling, whereas hydronic systems are typically used for heat only.  Hydronic systems are typically radiant floor heating systems, but could also utilize fan coils units.  Geothermal Heat Pumps essentially take heat from the earth during the winter and transfers it into the home, and during the summer transfer the heat from the home into the earth.

The system is comprised of three components.

1. Ground Coupling - essentially a well with either a closed or open loop piping.
2. Heat Pump - either water to air for forced air systems or water to water for hydronic systems
3. Distribution System - either ducting for forced air systems or piping for hydronic systems 

First Costs
As with standard heating systems, the size of the systems varies with the size of the house and the amount of insulation in the home.  With geothermal systems, a well will also be required. In some circumstances, the drinking water well can be used for the heating system as well.   Most homes will need a 3 - 6 ton system for heating and cooling loads.  Depending upon the well and "ground coupling" type, the overall system costs range from $800 - $3,500 per ton.
Currently, the federal government is offering a 30% tax rebate for residential geothermal systems.

Operating Costs

The operating costs of these systems are typically quite low.  For every unit of electricity that is used for heat, the systems is able to pull for units of heat out of the earth.  The break even costs vary based upon the prices of electricity, propane, oil, and natural gas.  In 1993, the EPA conducted a study in Burlington, VT to evaluate the efficiencies and cost of different types of heating and cooling systems.  They found the geothermal heat pump had the lowest operating costs as seen below.

• Geothermal - under $900/year
• Gas furnace with central air - approximately $1100/year
• Oil furnace with central air - approximately $1300/year
• Air source heat pump - nearly $1500/year