As an architecture enthusiast, I’m fascinated by historic buildings. There’s something magical about structures from decades or centuries past—they represent unique snapshots of design and craftsmanship from earlier eras. At the same time, most older buildings weren’t designed with energy efficiency and sustainability in mind. As demands grow to make buildings greener, historic preservationists face a dilemma: how can you upgrade historic structures without sacrificing what makes them special in the first place?

In this article, I’ll explore the nuances around improving energy efficiency in older buildings. Historic preservation matters deeply to communities—losing these touchstones to the past would be a cultural tragedy. However, with careful planning, it is possible to balance preservation and sustainability. I’ll discuss common challenges, and then provide some guidance around modifications that boost efficiency while maintaining architectural heritage. With creativity and compromise, the goals of honoring history and building a greener future don’t have to be mutually exclusive.

The Importance of Historic Preservation

Before diving into energy retrofits, it’s worth stepping back and asking—why does historic preservation matter in the first place? What value do old buildings offer, and why should we go to lengths to conserve them? There are a few key reasons:

For starters, historic architecture reflects the story of our past. Looking at designs from previous generations offers a tangible glimpse into bygone eras. The people who built these structures left marks of their values, aesthetics, lifestyles, and capabilities. Preserving this physical evidence of history helps communities retain a sense of identity and continuity with the past. It provides reference points for how culture and technology have evolved. Lose this heritage, and you erase clues to how society has changed over time.

Beyond just archaeology, old buildings often have inherent artistic merit. Historic designs showcase craftsmanship and architectural details you just don’t find in modern construction. Ornate woodwork, plaster medallions, stone carvings, stained glass, wrought iron, murals—the list goes on. Once lost, these vestiges of artistry can’t be recaptured. Demolishing historic buildings means abandoning these fingerprints of talented builders and architects. 

In a more practical sense, reusing structures also represents responsible resource management. Construction, even today, consumes massive amounts of energy and materials. Preserving past buildings reduces waste and environmental impact compared to building anew. retrofits often cost less than entirely new facilities as well. Additionally, updating old buildings helps spur economic activity and investment in established neighborhoods rather than abandoning them.

Beyond arguments around arts, identity, and ecology, surveys show that most people simply find older architecture more visually appealing and relatable. That shouldn’t be surprising—heritage sites become tourist attractions for a reason. People value connections to history and human-focused design over cold, mass-produced modern structures. Historic architecture’s enduring popularity is itself a testament to its worthiness of preservation.

Fortunately, governments and nonprofits have invested significantly in conserving historic buildings over the past decades. The National Register of Historic Places provides designation and recognition. Tax credits incentivize sensitive rehabilitations. Nonprofits like the National Trust advocate politically to strengthen protections. However, preservation ordinances have limits—as the next section explores, they can also create hurdles for trying to upgrade old structures.

Challenges of Improving Energy Efficiency in Historic Buildings

Many older buildings are notoriously inefficient in their energy use. They often lack adequate insulation, leak substantial air, have outdated HVAC systems, and use inefficient lighting systems like incandescents. While some charming Victorian homes evoke musty charm, most historic buildings need substantial efficiency upgrades to align with modern sustainability standards and energy codes. However, doing so can be complicated and costly.

The Secretary of the Interior’s Standards for Rehabilitation provide guardrails meant to ensure historic integrity is retained during building improvements. Essentially, upgrades should not radically change a building’s defining characteristics, spaces, openings, and sight lines. Original wall and window dimensions, layouts, and distinguishing features should remain intact. While well-intentioned, these rules mean you can’t fundamentally reinvent an old building to align with contemporary energy-focused design.

Making matters more complex, energy upgrades often trigger additional accessibility, egress, sprinkler, and seismic requirements. Integrating elevators, stair enclosures, new piping, and structural reinforcements without damaging ornate period details is no easy feat. Doing so can require extensive additional repairs at great effort and expense. The complexity of accommodating regulations while respecting heritage value causes many owners to throw up their hands and abandon efficiency goals.

Another barrier is the difficulty assessing costs and benefits for unique historic structures. Standard energy models and audit tools designed for typical buildings don’t always translate well. Bizarre floor plans, obsolete materials, fragmented records, and odd retrofits over the years foil attempts to estimate savings. Builders lack experience bidding projects with high preservation constraints. Securing financing for unconventional upgrades also proves challenging.

Ultimately, despite strong desire, building owners often resist green retrofits to avoid regulatory delays, unexpected costs, or unintended damage to architectural fabric. However, with care and creativity, it is possible to craft solutions that improve energy efficiency without undermining heritage character. The following sections highlight some promising approaches.

Strategies for Balancing Preservation and Sustainability 

While reimagining historic structures requires delicacy, thankfully options exist to upgrade energy performance substantially while maintaining architectural integrity. The key lies in careful sequencing, selective modifications, and smart technologies. With proper design guidance, historic buildings can meet greener standards without sacrificing character. The following strategies provide a menu of design options for approach.

Improvement of the Building Envelope

Starting with upgrades that have minimal visual impact helps acclimate preservation boards to a project. Plus, envelope improvements deliver solid energy savings for relatively reasonable costs. Air sealing and insulation boosts can be applied discretely:

– Adding insulation in attics, unoccupied crawlspaces and basements avoids disrupting interior spaces. Densepacking side cavities between wall studs also avoids exterior disturbance. 

– Caulking and weatherstripping doors, windows and joints cuts drafts while retaining existing openings and materials. Aeroseal technology can seal hidden cracks inaccessible via normal methods.  

– Patching damaged plaster or siding maintains visual appearance while improving thermal performance. Low-e storm windows also reduce heat loss without altering window dimensions or details. 

 envelope improvements don’t interfere with ornate interior finishes or exterior facades, making them ideal early phase upgrades. With minor ingenuity, insulation, sealing and selective material repairs cumulatively create major performance gains.

HVAC and Mechanical Upgrades

After basic envelope measures, upgrading heating, cooling and ventilation systems provides the next opportunity for energy savings:

– High-efficiency boilers and chillers can often replace dated equipment within existing mechanical rooms and shafts. Variable speed drives modulate output to match needs.

– Creative ductwork routing through unoccupied spaces like basements allows installing new air distribution systems with minimal intrusion. Zonal controls better regulate comfort.

– VRF mini-split systems provide localized conditioning using compact wall-mounted fan coil units. More zones improve comfort and efficiency versus central HVAC.

– Energy recovery ventilators introduce fresh air while transferring heat or cool between the incoming and outgoing streams. This improves indoor air quality without energy penalties.

Since HVAC equipment sits largely out of sight, upgrades impact heritage spaces minimally. Zoned systems also better serve irregular room configurations in older buildings.

Lighting Enhancements  

Lighting overhauls are relatively non-invasive but deliver massive efficiency gains. Solutions like LED retrofits and fixtures cut lighting loads by up to 80%:

– Replacing bulbs and fixtures avoids altering original wiring and luminaires. LED equivalents replicate temperature and light quality well, maintaining ambience.

– Light levels tune to balance highlighting ornate features versus suiting modern tasks and needs. Dimming and optical design enable flexibility.

– Smart controls like occupancy and daylight sensors reduce waste, improve usability, and avoid control clutter. Networked systems allow sophisticated schedules and scenes.

Since lighting modifications are largely equipment swaps or adds, they avoid risks to historic fabric. Better quality lighting also helps appreciate a building’s architecture and finishes.

Water Conservation Efforts

Water upgrades represent simple savings opportunities:

– Low flow faucet aerators, showerheads and dual flush toilets maintain original plumbing fixtures while conserving water.

– Pipe insulation reduces hot water waste from long distribution runs to distant taps. Recirculation loops provide hot water faster without purging cooled water down the drain while waiting.

– Submetering measures building, apartment or fixture-level usage, helping identify leaks and target reduction opportunities. Data enables further upgrades.

Bathrooms can represent some of the most ornate spaces in historic buildings, so preserving original tiling, sinks and other features helps maintain aesthetic integrity. Focusing on operational improvements and data metrics limits physical interventions.  

Use of Renewable Energy

Finally, on-site power generation through renewable energy offsets grid energy use. Options like rooftop solar, geothermal wells, small scale wind and solar hot water can often be integrated discreetly:

– Solar PV arrays situated on rear rooftops or grounds away from street sight lines generate emissions-free power. Lower panel costs continue improving project viability. 

– Geothermal or geoexchange systems leverage the constant temperatures of subsoil to provide heating/cooling. While excavation work is required, the payoff is very low energy bills.

– Small wind turbines on expansive hidden grounds also generate power, especially for remote historic sites. The renewable power offsets fossil fuels.

Renewables reduce energy costs without sacrificing parts of the building which contribute to heritage value. Onsite generation decreases the environmental impacts of operating historic structures.

Conclusion

At first blush, historic preservation and energy efficiency seem at odds. However, with careful solutions, we don’t have to sacrifice history for greener buildings. Historic architecture and culture matter – these sites represent who we are and where we came from. But it’s also critical that historic buildings reduce energy waste and carbon footprints. Thankfully, targeted building science improvements combined with sensitive technologies enable substantial efficiency gains without irreparably altering heritage fabric. With proper design guidance, historic structures can meet modern needs and standards. In the end, being wise stewards of both natural and cultural resources is important. By creatively balancing preservation and sustainability, communities can have their heritage cake and eat it too.