Architecture

Barn meets loft in savvy energy positive home design

Barn meets loft in savvy energ...
The Solar Barn Loft is described as compact yet spacious, with an open-plan layout that has the potential for a variety of different interpretations
The Solar Barn Loft is described as compact yet spacious, with an open-plan layout that has the potential for a variety of different interpretations
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The Solar Barn Loft is described as compact yet spacious, with an open-plan layout that has the potential for a variety of different interpretations
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The Solar Barn Loft is described as compact yet spacious, with an open-plan layout that has the potential for a variety of different interpretations
The house features a solar panel array on the roof, a large patio that reflects light into the house and nearby deciduous trees that block the summer sun
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The house features a solar panel array on the roof, a large patio that reflects light into the house and nearby deciduous trees that block the summer sun
The roof uses an inverted scissor truss upon which the 48-panel photovoltaic array is installed
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The roof uses an inverted scissor truss upon which the 48-panel photovoltaic array is installed
Reflective fins are used to help light the inside of the house naturally
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Reflective fins are used to help light the inside of the house naturally
The angle of the roof is optimized for solar exposure to the solar panels and also to allow air to flow through the house
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The angle of the roof is optimized for solar exposure to the solar panels and also to allow air to flow through the house
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Inspired by the New England barn and the New York loft, Architect Paul Lukez has penned a cleverly compact home design that uses natural ventilation, "super insulation" and passive and active solar systems to minimize energy use.

The 2,000 sq ft (186 sq m) Solar Barn Loft uses overhangs and openings on the southern façade to minimize solar heat gain in the summer and maximize it during the winter. Deciduous trees block the summer sun, but allow winter light through. A large patio bounces light upward towards the underside of the south-facing eve, which itself is reflective and helps to light the house naturally. Heat, meanwhile, is not reflected.

The roof uses an inverted scissor truss upon which a 48-panel photovoltaic array is installed. According to Lukez, the array would (conservatively) generate around 16,300 kWh of electricity per year. The building, he estimates, would use only around 14,905 kWh per year, leaving a healthy surplus.

The angle of the inverted scissor truss roof is optimized for exposure of the solar panels to sunlight and also to allow air to flow up through the house. Spaces inside the truss can be closed off when it is cold and can be opened up for natural ventilation when it is warm. There are also air ducts to bring cold air in through the basement of the house that can be opened and closed as required.

The house features a solar panel array on the roof, a large patio that reflects light into the house and nearby deciduous trees that block the summer sun
The house features a solar panel array on the roof, a large patio that reflects light into the house and nearby deciduous trees that block the summer sun

The design employs "super-insulated walls" with a double wall cavity that is filled with blown cellulose. Icynene spray-in-place soft foam insulation is used in the roof, which is 100 percent water-blown and, as such, does not contain environmentally harmful blowing agents. In addition, the design features triple-glazed windows and 4 inches of rigid insulation below the basement floor slab, all of which should add up to very high levels of thermal insulation.

A 12-in (305-mm) thick concrete slab provides thermal mass for the southern half of the ground floor. The slab is heated up by the sun during the day to warm the house at night. On warm night, windows can be opened to keep the house cool.

Elsewhere, flooring and siding in the house is made from wood and recycled materials and the driveway and other paved surfaces are semi-porous. Roof water is collected for use in toilet cisterns.

The Solar Barn Loft project was designed as part of a competition sponsored by the US town of Northampton, Massachusetts. Lukez explains that the town provides land to prospective home owners at nominal cost if they use one of the winning zero-energy designs.

Although construction of a Solar Barn Loft has yet to begin, Lukez says there have been a number of inquiries and that he expects to secure a build within a year. Construction would take around another 12 months at a cost of between US$500,000 and $600,000.

Solar engineering and calculations by Derek Brain of Transformations Inc.

Source: Paul Lukez

View gallery - 5 images
4 comments
Vince Pack
500k is still high in my market for 2000ft/sq, but we're definitely getting there! It's really nice to read about the encouraging use of sustainable building practices, renewable energy powered, and very thoughtfully designed housing while also including a projected price.
WilliamWhite
I agree with Vince. I know I could build a home close to the same efficiency as this for half the cost. The majority of people who could afford this home would want something bigger and could care less about the efficiency. And 48 panels-what are they doing starting their own power company? Most of us get buy with a fraction of that number both with and without battery backups.
Don Duncan
A forty year old passive/active solar design with vague descriptions like "super insulation" and "high level of insulation". The R-value of state of the art insulation is known. All you have to do is read and it doesn't say "super" or "high". Double wall cavity is a waste of space only needed if foil-backed foam (poly-iso) is not available (3rd world). It's not expensive here considering it lasts as long as the house paying for itself every day. So many builders underestimate the value of ultra insulation. The problem is buyers/homeowners who are ignorant and therefore don't demand better construction. They wind up paying extra for heating/cooling because a builder saved himself pennies, costing the enduser dollars.
It's sad that most people buy houses like they buy everything else, with no input. The most important and biggest investment one will ever make is his shelter. And eliminating the general contractor/realtor by being an owner/builder means a million dollar house could be obtained for 25%-50%, and that's not taking into account the interest saved on a mortgage over 15-30 years, which could be another million or more.
What would rather do, spend a year self educating in your spare time so you can be your own general contractor, or spend an extra 10-20 years working at your job?
Charles Barnard
Yet another building which cannot handle high winds.
The emphasis on PV systems in today's solar designs is distressing since the optimal economic use of solar is as heat and light.
The exterior of this building looks certain to generate some nasty swirling cold winds and drifts in winter too.