NextGen Homes

NextGen Home rendering by WM Whitaker Landscape Architects

I joined the board of green|spaces this year. If you don’t know about green|spaces and the great work they’ve been doing for almost 10 years now, please head to www.greenspaceschattanooga.org to find out more. They are a nonprofit dedicated to advancing the sustainability of living, working, and building in the Chattanooga region.

One of green|spaces’ recent efforts to that end is building a group of homes called the NextGen Homes that will attain net zero energy use and putting them on the market for sale. Coming in at a reasonable $360,000, the NextGen houses are intended to demonstrate that smart, super energy-efficient housing is attainable right here and now in Chattanooga. To understand what a big deal this is, check out this article from the Wall Street Journal highlighting a model net zero house listing for $2.5 million and quoting builders who think net zero is not “commercially available” or “affordable.” 

The first of four planned NextGen Homes is under construction now, and I’m pleased to be part of the team working to create, build, and sell this project. I look forward to deploying some of the smart building strategies we used here in future projects.

In order to get Net Zero Energy Certification (see here for info about the certifying body), a building has to generate as much energy as it consumes. To do this we design the house to use a minimum of energy and then design a solar array to meet or slightly exceed that energy usage. It may sound intimidating or hard to do, but the tactics we’re using here are common-sense approaches that can be used for any single-family home.

Siting and exposure. Of course we positioned the house to ensure year-round sun on the portion of the house that was going to get a solar array, but we also used the roof overhangs to provide summertime shade for the windows on the south side of the building. The east and west openings will be protected by deep porches or operable shutters.

Insulation and air-sealing. The insulation in the walls, floors, and ceilings of a house are what hold the heat or cold inside or out depending on the time of year. Fiberglass batts, the convenient and common solution, are not the most energy-efficient to begin with, and poor installation can reduce their effectiveness even further. So instead, we are using a Greenguard Certified spray-applied open-cell foam for the ceilings and crawlspace. The foam has a much higher insulation factor than batts, serves also as an air barrier, and helps with air sealing at joints and crevices. Of course no amount of insulation will help if the wind can blow right in around windows, doors, or electrical outlets. Which is why today we install some form of vapor-permeable air barrier. Like Gore-Tex for a house, the air barrier repels liquid water, allows water vapor to escape, and holds in the conditioned air. Air barriers take many forms—from building wraps to peel-and-stick sheets to rolled-on liquids— and the technology is always changing. The NextGen Home will use a self-adhered sheet with matching tapes to seal around windows and doors.

High-efficiency heat pump and energy recovery ventilator. Because when you seal everything up really tight, you actually do have to introduce fresh air through mechanical means. The benefit of doing this on purpose (rather than through a drafty window) is that the fresh air can be cooled or heated as it is introduced, and that reduces the load on the heating and cooling.

Solar array. The construction measures discussed above keep the house from using too much energy, but the other part of the equation is the 6 kW solar array, which will let the house generate enough renewable energy to meet its own needs.

Smart water use. Things like low-flow toilets and faucets reduce general water use. Pervious pavers on the patios and driveway let water through to the ground and keep it from running off into the streets and sewer system.

The house is currently under construction at 631 Hamilton Avenue on the North Shore, and should be completed by early summer. To see it in person, you can take one of green|spaces' regular tours as construction proceeds (info on tours here). 

Project team:

green|spaces

Workshop : Architecture

WM Whitaker Landscape Architects

Collier Construction

Grace Frank Group

Taking Shape

A residential project I’ve been working on is taking shape now. This is one of my favorite parts of the process—when I can articulate in three dimensions all the wants, needs, and aesthetic leanings the client and I have discussed.

In this case, my clients are a couple with a grown son who want to create their “forever” house. They are art lovers who create and collect art, so the home will incorporate a studio and serve as a showcase for the works they own. The clients are also looking for spacious open plan living, a generous master suite, a guest bedroom and bath, space to house books, pleasant outdoor spaces and gardening opportunities, and a well-planned, light-filled kitchen.

One major goal is to provide a gracious living experience with all the functions the clients want in 1,900 square feet, with a cost of less than $175 a square foot. (Keep in mind that the average square footage of new homes currently stands at around 2,700 square feet, and the average cost per square foot is around $150.) The clients and I agree that we want to spend money on generous gestures that add to the everyday living experience—such as a folding window/wall system that will allow the back wall of the living space to virtually disappear—and economize on other elements.

The sloped site is on a busy street near a five-way intersection. To screen the home from the noise and visual clutter of the street, I’ve placed the garage and an enclosed brick courtyard at the front of the site. A covered walkway connects the garage to the house. The clients can create a rich visual experience for entry to the house through plantings and sculpture in the courtyard.

Inside, I’ve continued to protect the home’s views and privacy by placing the windows high on the wall adjacent to a neighboring rental property. The high windows will let in light, while the solid wall below will provide privacy—plus space for artwork display and built-in shelving in the open plan living and dining space. Views are directed out toward the back of the house, where the folding window/wall system will open the back wall to a screened porch. The site slopes enough here to allow the porch to be in the treetops.

The master bedroom, art studio, and kitchen complete the first floor. Upstairs, a guest bedroom will also function as a library, completed with a reading nook that looks over the wooded lot. The bedroom opens to a rooftop deck that overlooks the courtyard—another connection to the outdoors and gardening opportunity.

Stylistically, the exterior form of the house is modern and clean, but not too aggressive: we wanted the house to be in the same family as the 1920s cottages close by. The overall modest size as well as the pitched roofs and lap siding help us to be good neighbors.

The project is currently out for pricing with New Blue Construction (http://newblueconstruction.com). We've all got our fingers crossed that the pricing will come back on target. The next step will be to adjust for any overages that might come up in pricing, and then on to construction.

Meanwhile in Nashville...

Project: Snyder Court
Developer: Nuck & Beal
Location: East Nashville

I’ve been working on a new project that should break ground in East Nashville this fall. Called Snyder Court, it’s a development of 4 single-family houses aimed at first-time homebuyers. Each unit is roughly 2000 square feet and has 3 bedrooms. Some of the units have 2 full and 2 half baths, and others have 3 full and 1 half bath.

Each project has unique challenges and this one is no different. In this case, there were three particular challenges to solve, and here’s how the client and I handled each issue:

Providing a gracious, dignified living environment in a small footprint

Clearly, on a small lot, we had to go tall to be able to provide 2000 square feet of living space. The bottom floor of each unit contains the garage, a porch, and an office or bedroom. The kitchen and open plan living space are on the second floor, with additional bedrooms on the third floor. We located a bath on each level for easy access. The porch on the ground floor and a balcony on the second floor extend the living space outside and are sheltered from the street by a two-story wood screen. Each unit is defined with a pop of bright color that frames and accentuates the screened area.

Getting these tall (3-story) houses to fit in with the scale of the current housing in the neighborhood

Although going to three stories let us provide plenty of living space, it presented another challenge—these houses could potentially loom over the existing buildings on the street. I worked hard to bring the scale down by finessing the roof lines, pulling the eaves down so that the third floor felt more like an attic story and the overall volume felt more like the conventional 2-story houses already in the area.

Creating privacy on a busy street

These houses will be on a street with a fair amount of traffic and noise. To give the homeowners privacy and shelter, I created wrap-around screening that extends up to the second floor. These screens will allow plenty of light to flood the living spaces while also blocking out the hectic sights and sounds of the busy street.

Site Analysis

It's important to understand what nature gives you. How steep is the land? Where does the sun rise and set? Is there a view? What about wind, or flooding, or an unattractive view or unwanted noise?

This project will require some unusual shading and screening strategies to minimize unwanted noise and bring in natural light. There's a busy intersection to be screened and the rising sun is shining directly along the length of the site in mid-summer. On the plus side of the ledger there are a couple of beautiful oaks, there's a winter view to the north, and the entrance from the road is nice and level.

I map everything of interest, both good and bad, by hand over a topographical map of the project site. This gives me my first clues about where to locate certain rooms, and where and how to place windows. As soon as I have a working floor plan I'll refer back to my site analysis to be sure I'm on target with the project goals - minimizing unwanted noise or unattractive views while maximizing light, and balancing views, and privacy.

Herding Cats

One of the first steps in designing a project is figuring out the program. This is just a written list of the spaces along with anything that may be known about them. Sometimes it's pretty simple:

"We'd like to add a master bedroom and bath. The bathroom should have a shower but we don't need a tub." "Oh, and we'd like two sinks in the vanity."

Sometimes it runs for pages and pages with detailed room descriptions and adjacencies. The program for the project I'm working on right now is a little over two pages and includes everything that the client could think of as well as everything I could think to ask. The project is a house of only 1500 square feet so it's pretty detailed. My clients for this house are artists as well as dedicated cat people so one interesting wrinkle in this problem is controlling access to various parts of the house for the felines.

That's right. This morning I'm herding cats.

Why do it?

Architecture is hard. Trying to do it better is REALLY hard. So why do it? Because...