Stott Architecture
 
High-End Green in the Hamptons
Climate Zone 4, Sagaponack, NY
Originally published in Green Building Advisor
by Richard Stott

Read it online here
 
A luxury spec house on Long Island seeks certification from six green building programs
 
The Hamptons are flush with poorly built, energy hog spec homes on an acre or two. Many of these homes have huge lawns, pools, tennis courts, and koi ponds. Most are thankfully hidden by tall privet hedges. Of course, the Hamptons are also known for some of the most extravagant and well-built residences in the world. All of these estates, well-built or not, require an army of maintenance workers to keep them tidy and presentable.

When the maintenance and utility bills began to pile up for his own home, a developer named Michael Newmark of Newmark Developers decided to stand up for sustainability. In the fall of 2012, I received a call from Michael; he wanted a whole new approach to delivering a high-end spec house. His site, nearly 4 acres of oak forest on eastern Long Island, had no views, no waterfront, and no topography.

The developer had finished a number of homes in the same area, all of traditional style and construction, but none of them paid the slightest regard to energy or environment. Our firm had finished our first LEED Platinum home in 2010 and we remain committed to delivering efficient, healthy, and comfortable buildings. So we began a dialog on how to deliver a luxurious, sophisticated home that saves energy on every aspect, from the utility bills to the landscaping, and is much less demanding on the environment.

After a few meetings with the developer, we came up with a wish list that we thought would be appealing to high-end second homeowners looking for something different. The program called for the usual indoor spaces, but we added some “points of interest” so that our spaces shared a common connection and made the home fun and entertaining by design.

The theme (or “parti”) was “a modern green barn.”

Design outline

Here is how we conceived the design. First Floor:
• Grand entry and daylit stair both up and down
• Open-plan living/dining/kitchen with deck that connects to pool and outdoor dining
• Separate pantry closet
• Powder room
• Master suite
• Large laundry room
• Second bedroom/office with in-suite bath
• Three-car garage with plenty of daylight Second Floor:
• Junior master suite
• 2 additional bedrooms with in-suite baths
• Catwalk connection to open loft space Lower Level:
• Open to the basement-level courtyard
• Home theater
• Large workout room with outdoor space
• Wine room
• Mechanicals
• Playroom/bedroom, open to courtyard

The plan for the exterior was to include a 60-foot lap pool, terraced garden, a subterranean courtyard, parking, and low-maintenance landscape features. A tennis court is optional. We also included space for an elevator, to be constructed or not depending on the buyer's wishes.

We agreed to use the most advanced building science and materials available and wanted a clearly defined break from the common wood-frame construction, gambrel roofs, and enormous landscapes.

Design considerations

The Sagaponack Modern Green Barn is basically two barn shapes, a one-story and a two-story section, with a connecting link that houses the entry and stair. The house is oriented with the long axis running east/west, exposing the maximum wall and roof area toward the south. Both the one- and two-story sections open to the courtyard and south-facing glass takes the form of triple-glazed bifold doors (U=0.12) by Intus to allow the house to be completely open to the outdoors, yet provide exceptional thermal qualities. Windows on the north side are minimal, but enough to allow for balanced daylight and views.

The barn concept can take many forms and we looked closely at the Long Island potato barn for inspiration. Potato barns are built partially in-ground and constructed with exterior facing concrete pilasters for structural support. We used the pilaster concept here to house steel columns where necessary for balconies and decks and also to provide chases for the leaders from the wide built-in gutters. The gutters also eliminate the need for snow guards or rails. The pilasters are built under the wide overhangs which protect the glass from summer sun yet allow sunlight to stretch across the floor to the north wall in winter.

SIP walls and roof

Another innovation in our construction process is the use of specialized R-36 structural insulated panels (SIPs), 8 inches thick, for the walls. We specified magnesium oxide panels for the walls and 10-inch thick, R-42, steel-skin SIPs for the roof/ceiling.

All of the exterior walls were constructed with magnesium oxide skin panels. The exterior was simply stuccoed and the interior was taped, spackled, and painted. The metal-skin roof SIPs were installed and immediately, the house was dried in — a big advantage.

Again, to save labor and the number of trades on the site, we simply cleaned up and painted the interior metal skin of the roof. Every major room in the house has a cathedral ceiling, so the finish process was much less complicated. Every panel joint connection from the basement to the top of the roof ridge is spray-foam-sealed during the joining process to assure a tight fit.
A tight construction schedule

The project had to be completed quickly and the timeline did not allow for the common design-bid-build scenario. I knew we had to get a contractor on board from the start in order to get the project completed on time.

Enter John Barrows, a contractor, partner in Performance Path Solutions, and green building lecturer for the NAHB. Performance Path Solutions represents and distributes Superior Wall foundation panels as well as both magnesium oxide skin and metal-skin SIPs. After meeting with John, the developer decided that a fast-track building process with John would be his best chance to get the product he wanted in the time frame allowed.

The panel distributor, Oceansafe, provided us with engineering for the wall and roof systems and Superior Wall Foundations provided us with the necessary engineering for the foundation and floor system.

Since the majority of the basement level is occupied space, we agreed that the Superior Wall system was the best for our project. For foundations installed in winter, the Superior Wall system has the added benefit that it can be constructed during freezing temperatures. The Superior system does not require a poured concrete footing; rather, the 10-foot wall panels are placed on a thick gravel base. Backfill and the poured slab over rigid insulation lock the wall in place. Rigid insulation under the slab provides a continuous thermal break and significant thermal mass for the lower level.

The thermal performance of the of the R-21 foundation walls was increased by adding R-13 batts on the interior, similar to standard cavity-wall insulation. This system required the use of dead-men reinforcing opposite the open walls to the courtyard in order to resist soil pressure. If walls and floor diaphragms are not properly connected, the foundation could be pushed out of plumb during the backfill operation.

We designed the floor system with Weyerhaeuser I-joists. The subfloor consists of 1 1/8" thick tongue-and-groove Boise Cascade Sturd-i-floor throughout the main and upper floors. Michael George, a local Weyerhaeuser rep, assisted with the floor and diaphragm engineering. The only independent engineering we needed was for the retaining wall that defined the lower courtyard.

We broke ground in May 2013 and finished 15,000 square feet of constructed space, which includes the pool, patios, terraced garden, and courtyard, in 16 months. The weather during the winter of 2014 on Long Island was particularly bad; there were numerous days when nobody could get to the building site. Temperatures were well below normal, but every time the sun was shining, the building was warm enough to work inside.

Daylight and nightlight

During the day, sunlight enters every space from ridge skylights and the gable ends made of Kalwall. The Kalwall has an R-8 thermal rating. The daylight inside is amazing and every room on the main and upper floors is filled with even soft light.

As the sun sets, the transformation from dusk to dark is almost magic. The impression is that every place the daylight enters now gives up a warm soft glow to the outside. The four major gable ends and ridges shed a soft interior light and the pilasters light up as well. By lining the inside of the pilasters with Solexx (twin-wall 5 mm polycarbonate) and covering them with 1x4 FSC-certified African mahogany called Sapele, each pilaster becomes a soft glowing lantern as daylight fades to black.

We built a mockup of the pilaster and tried numerous types of dimmable LED rope lighting, but found in the end that a simple soffit-mounted LED was enough to spread the light evenly throughout the pilaster. As the job progressed, we called the pilasters “lanterns.” Where the lantern extended more than one story, we used another LED can-light for each additional level.

The polycarbonate film behind the mahogany slats mimics the slatted barn doors and appears to have the same substrate finish. So during the day, the pilasters look to be constructed in the same way as the stucco exterior walls. At night, with dimming options, the lighting effects are infinite, and the variations of lighting scenes completely transform the appearance and mood of the exterior.

A hydro-air heating system

Mechanical, electrical, and plumbing are important considerations, especially in a SIP building. We organized the mechanical systems to be as efficient as possible. The center of the two-story space contains the main mechanical room. The main mechanical room contains a Weil-McClain Ultra 230 boiler (AFUE 95 with modulating controls) and one of three air handlers which serve the main and lower floors. The room also contains an energy-recovery ventilator (ERV) for the north wing and the 400-amp main electrical distribution box.

Most of the bathrooms are oriented close to this mechanical core to keep plumbing and electrical runs short where the majority of hot water is needed. The only hot water requirement in the south wing is the kitchen and powder room, which are served by an on-demand water heater in a closet below the kitchen.

The south wing and connecting link are served by a fourth air handler in the basement mechanical room (mechanical room #2) at the east end of the south wing basement, where the second ERV is located.

The central area of the two-story space (where the bathrooms are located) has a flat ceiling, and the attic above is a perfect location for the third air handler to service the second floor.

A sunlit courtyard

The courtyard is the hinge point. Most spaces have direct access to the courtyard in the form of views, balconies, or doorways. Sunlight not only fills the courtyard, but reflects off the south-facing glass and lights up the covered outdoor space under the deck off the kitchen. Daylight even makes it back under the kitchen to the workout room under the south wing. The retaining wall of the courtyard is stucco, and a perfect place to project movies. The courtyard floor is covered in ¾-inch-thick stone and becomes a playground to the house with access to each floor.

An indoor playroom/bedroom with an attached bath is located at the lower level, accessible to the court. The level also has an additional full bath, which serves as a cabana for the pool. The main stair extends to all three levels and overlooks the court from every step. The main stair with extensive views of the courtyard terminates at the lower level gallery, a perfect place to display art and sculpture.

An outside stair rises as part of the terracing to the main-level patio, Jacuzzi, waterfall, and pool. The waterfall, an infinite edge at the pool, spills into a trough and creates a soft “white noise.” From the far side of the pool, it appears that the water is spilling into the court. As the stair rises, each terrace level is accessible from the stair. The irrigated terrace garden can be planted with almost any type of plants, including vegetables.

The master and junior master bedrooms include balconies that overlook the courtyard and provide privacy from the terrace and outdoor dining areas.

When children visit, they never stop running

The house is a fun place to be. The courtyard can be accessed from almost every room and there are numerous ways to move through the house both horizontally and vertically. Although we planned for a round clear glass full-access elevator by Visilift, it has not yet been installed. It remains an option.

The second-floor catwalk and loft lead from the bedrooms to the main stair and also to a second-floor deck with a spiral stair to the ground level. We’ve found that whenever people visit, especially children, they are seen running from one level to the next, inside, outside and in between — and they never seem to stop. The whole house becomes a playground.

A three-car garage

The unheated three-car attached garage is a daylight magnet. The Clopay ‘Avante’ doors are translucent and compliment the north and west walls which are constructed of single ply polycarbonate sheet, which we cut into each stud bay.

The wall studs are cedar and left exposed with no finish.

Tile floors

We wanted to keep the materials simple and clean. We used modern materials that fit our LEED goals and look great together. The floors (all but the bedrooms and theater) are porcelain tile by Casalgrande Padana (Dragon Grey).

Since all the doors of the living room open fully to the patio, we wanted to share the interior and exterior floor surfaces, so we used the same tile size, color, and pattern on the outside, only with a grip surface. This color will not overheat in summer and really brings the two spaces together. The grey tile extends down the exterior stair and covers the horizontal surfaces of the terraced garden.

The lower gallery space is also tile. All ceramic tile is laid on Schluter-Kerdi waterproofing membrane.

We used only two types of wood for the project. The bedroom floors and all the trim is the same Sapele mahogany that we used for the exterior features and works well with the FSC-certified doors from ETO doors.

The other wood source is the Weyerhaeuser Parallams (PSLs) which we used for rafters, girders, support girts for the skylights, all the framework for the loft over the kitchen, and the entire catwalk and stair structure. The PSLs are sanded smooth and left exposed.

All interior door and window trim is also Sapele mahogany, treated with one coat of Penefin, which really brings out the richness and color. The mahogany floors and decking are left untreated. The theater and playroom are carpeted and the workout room has rubber workout flooring.

The gray standing-seam metal roof is Kynar-finished 24-gauge steel.

Lessons Learned

Get your contractor on board early. Rated, sustainable projects require special attention and expertise. I believe it is far better to hire a knowledgeable contractor during the design phase and review the project with the whole delivery team often during the design development and construction document phases of design. A design-bid-build type delivery would be much difficult to document fully and much more risky.

Precast concrete foundation panels.
The Superior Wall foundation system is great, but it must be installed carefully and reinforced according to the engineering included with the design documents. Failing to install all the diaphragms, supports and back-up reinforcement will result in walls being out of plumb.

Airtightness. Although all the SIPs are locked together and sealed with foam, be sure to check all connections between systems to assure that no gaps are left. We found some fist-size holes at the connection between the SIPs and Kalwall gable connections that were hidden and went unnoticed until we ran a blower-door test.

Plan ahead for wiring runs through SIPs. Carefully plan all lighting locations and pick fixtures before construction. SIPs are adaptable to wall switches and outlets, but it's better to avoid placing wires, conduit, or piping in the perimeter walls if possible. Review the lighting and power plans with the SIP manufacturer and installers before they start.

Beware of hairline cracks when plastering over SIPs.
The base and finish coat stucco system on the exterior went off without a hitch. When it came to taping and spackling the interior surfaces, however, we found some hairline cracking at the joints. We believe this resulted from the normal building “curing process” and was telegraphed to the panel joints due to the rigidity of the panels. This was solved by the use of an elastic bedding compound (same as used on the exterior stucco) and an elastomeric paint used as the primer.

Polycarbonate issues. Polycarbonate is a wonderful material, but it expands and contracts like crazy and is prone to condensation. Be sure of your attachment details.

Richard Stott, AIA, LEED AP
 
General Specs and Team

Location: Climate Zone 4, Sagaponack, NY

Bedrooms: 6

Bathrooms: 7.5

Living Space: 8860 sqf

Cost (USD/sq. ft.): $470/sqf

Architect: Richard Stott, AIA LEED AP, Stott Architecture

Developer: Micahel Newmark, Newmark Developers

Builder: John Barrows, P3 Builder Group

Construction

Foundation: Superior Walls Xi+ precast concrete panels - R-21 delivered + R-13 fiberglass batts added inside

Slab insulation: 2” thick XPS

Above-grade walls: MagWall Building Systems SIPs with R-36 EPS

Siding: Stucco applied directly to the SIPs

Exterior trim: Unfinished Sapele FSC-certified mahogany

Windows and glazed doors: Intus Eforte vinyl windows – average U-factor=0.14

Translucent glazing system: End walls and ridge skylights by Kalwall (U-factor=0.20)

Timber framing: Weyerhaeuser Parallam PSL engineered lumber

Floor framing: Weyerhaeuser Trus Joist I-joists

Roof / ceiling construction: Oceansafe 10" thick SIPs with 25 ga. steel cladding (R-45)

Roofing: Standing-seam metal roof by I-metal

Space heating: Weil-McLain Ultra 230 propane-fired boiler (95 AFUE)

Cooling: Carrier 16 SEER variable-speed air conditioner

Ventilation: Santek variable-speed ERVs (2 units)

Domestic hot water: Indirect 80-gal. SuperStor water heater connected to the boiler; system has a hot-water circulation pump activated by motion detectors.

Energy

Blower door test results: 2.66 ACH @ 50 Pa (average of pressurization and depressurization multi-point tests)

Estimated site energy use: 182.2 MMBtu (projected to be reduced to 168.7 MMBtu with future installation of 3-kW PV system); estimated energy cost for heating, air conditioning, domestic hot water, and miscellaneous electrical use is $6,311 per year.

Actual energy use: Unknown; house is not yet occupied

PV: The plan is to install a 3-kW PV system on the south-facing roof; once this system is installed, the house will have a HERS Index of 35.

Appliances: Energy Star rated appliances (where applicable)

Lighting: Oligo LED track lighting, recessed LED fixtures

Swimming pool and Jacuzzi: Installed 3” water-supply pipes with wide-sweep elbows and a variable-speed multi-stage pump. Filter medium is recycled glass instead of sand.

Water Efficiency

• Low-flow plumbing fixtures • EPA WaterSense certification • Central plumbing core allows efficient pipe runs

Indoor Air Quality

• Low- and no-VOC paints • Solid wood and tile flooring • Balanced ventilation system provides fresh air to living spaces and bedrooms

Green Materials and Resource Efficiency

• Prefabricated building components reduced waste and construction time • Engineered lumber and advanced framing techniques optimize material usage

Certification

The home will receive 6 third-party rating certifications.

1. The house is registered in the LEED for Homes program and we expect to attain at least LEED Silver.

2. We also registered under the National Green Building Standard (NGBS) ICC 700- 2012. We wanted to compare the complexity, cost and time to complete these two programs.

3. Department of Energy “Zero Energy Ready Home” ( formerly Challenge Home Program).

4. DOE Energy Star

5. DOE Indoor Air Plus

6. DOE Water Sense

Also a Home Energy Rating System (HERS) is required for LEED, for Energy Star, and for our own local municipality, which was one of the first agencies in New York to require HERS ratings for homes. In Southampton, the larger the home, the more efficient it must be.

We contracted with Steven Winter Associates and worked with Karla Donnelly from that firm, who is helping us with all six of these programs. Many designers and contractors are claiming that their buildings are built to LEED or NGBS standards, but the only way to know for sure is to have the certificate on the wall. I’ve found that the requirements of these rating systems are often a focal point for decision-making. On a project with no certificates, a material might be substituted or spec changed to save a few dollars. A subcontractor can (and often does) install a noncompliant item without notice. When documentation is required, disputes are minimized and the whole team works toward a common goal. The sustainability team, from the owner to the subcontractor, is strengthened, focused, and committed from the start, and an issue that might cause an argument or be fodder for a lawsuit finds an answer or solution in the rating requirements.