Denver Home Inspection Issues by Era - What to Expect by Decade

Denver, CO

Key Takeaways

  • Pre-1950 homes often have significant foundation movement and outdated electrical
  • 1950s-1970s brick ranches typically have original cast iron drains and aging mechanicals
  • 1980s-2000s homes may have polybutylene plumbing and EIFS issues
  • All eras face Denver's universal challenges: radon, expansive soil, and hail

Denver's housing stock spans from 1880s Victorians to current construction, with distinct building practices and materials characterizing each era. Understanding typical findings for your home's age helps evaluate whether inspection results are concerning or expected. Some issues transcend era—radon, expansive soil, and hail affect homes of all ages.

Pre-1920: Victorian and Early Denver

Denver's oldest surviving homes include Victorian-era houses in Curtis Park, Five Points, and portions of Capitol Hill, along with early 20th century homes in the Highlands and elsewhere. These homes have character but also over a century of Denver soil movement and system aging.

Foundation and Structure

Stone or brick foundations from this era have experienced 100+ years of expansive soil cycling. Some movement is virtually guaranteed. Look for significant differential settlement (one corner moving more than others), stair-step cracks in brick, and floor slopes. Minor settlement is expected; major ongoing movement requires professional evaluation.

Electrical Systems

Original wiring was knob-and-tube, often partially replaced over decades with various wiring generations. Complete rewiring is recommended for habitability and insurance purposes. Service panels are often undersized (60-100 amp) for modern needs. Expect $10,000-25,000 for full electrical update depending on home size and complexity.

Plumbing Systems

Original galvanized steel supply lines are typically failed or failing after a century. Original cast iron or clay tile drain lines may still function but are often compromised. Full plumbing replacement is common in restored Victorians.

Other Considerations

Lead paint (certain), possible asbestos in various materials, inadequate insulation, and single-pane windows are standard findings. Radon is typically elevated due to basement construction methods and building envelope gaps.

1920s-1940s: Bungalow Era

Denver's bungalow neighborhoods—Congress Park, Platt Park, Berkeley—developed during this period. These homes combined smaller footprints with solid construction and basement space.

Foundation and Structure

Poured concrete or concrete block foundations in this era typically show less severe movement than older stone foundations, though Denver's soil still creates settlement. Brick exterior construction is common and generally holds up well.

Mechanical Systems

Original boiler heating systems may still be present, though most have been converted to forced air. Original wiring was early cable types, often updated in subsequent decades. Cast iron drain lines from this era are reaching end of life now.

Common Updates Needed

Bungalows from this era typically need electrical panel updates, potential full rewiring if not previously done, HVAC modernization, and often roof replacement. Window replacement is common to improve efficiency.

1950s-1960s: Brick Ranch Era

Post-war development filled Park Hill, Montclair, and suburbs with brick ranches. This housing stock represents a significant portion of Denver's market and has characteristic age-related issues.

Foundation and Structure

Poured concrete foundations on these homes have experienced 60-70 years of soil cycling. Settlement is common but often stable. Brick veneer construction masks movement until cracks become significant. Basement slabs often show heaving from soil expansion.

Sewer Lines

Original cast iron or Orangeburg (tar paper) sewer lines are the most common significant issue in this era. Most are failing or will fail soon. Sewer scope inspection is essential, and replacement budgeting should be part of purchase planning.

Electrical and HVAC

Original 100-amp electrical service may be adequate but panels are aging. Original HVAC systems have been replaced at least once; current systems should be evaluated on their own merits. Lack of air conditioning is common—the homes were designed for Denver's milder historical climate.

1970s-1980s: Suburban Expansion

Continued suburban development brought different construction methods and some problematic materials now known to cause issues.

Polybutylene Plumbing

Polybutylene (PB) plastic piping was used from approximately 1978-1995. This gray or blue piping is prone to failure, particularly at fittings. Many Denver homes still have PB plumbing. Replacement typically costs $4,000-10,000 and is recommended, though not always immediately urgent.

EIFS/Synthetic Stucco

Exterior Insulation and Finish System (EIFS) appeared in this era. When improperly installed (common during the period), EIFS traps moisture and causes wood rot behind the cladding. Homes with EIFS require moisture inspection and may have significant hidden damage.

Construction Quality Variation

Rapid suburban development led to variable construction quality. Some developments from this era have persistent issues with foundation, framing, or finish quality. Research the specific builder and subdivision if possible.

1990s-2000s: Peak Suburban Development

Development peaked in outer suburbs during this period, with larger homes on smaller lots becoming common.

Foundation Engineering

Better understanding of Denver's expansive soils led to improved foundation design, including post-tensioned slabs and engineered pier systems. However, not all builders implemented best practices. Foundation issues remain common, though often less severe than in older construction.

Builder Grade Materials

Production building used lower-cost materials that are now showing age: failing water heaters, HVAC systems approaching end of life, and worn finishes throughout. Many homes from this era need comprehensive updating.

Landscaping and Drainage

Newer subdivisions sometimes have marginal lot grading and drainage. Combined with expensive landscaping that alters original drainage patterns, water management issues are common. Evaluating drainage is particularly important for this era.

2010s-Present: Modern Construction

Current construction benefits from improved codes and better understanding of Denver's challenges, though new homes aren't problem-free.

Radon-Resistant Construction

Most new Denver homes include radon-resistant features (sub-slab gravel, vapor barrier, capped pipe). However, these passive systems don't guarantee low radon levels. Testing is still essential, and many new homes require active mitigation.

Energy Code Impacts

Tighter construction for energy efficiency can create moisture issues if mechanical ventilation isn't properly designed. New homes may show humidity problems in winter and require dehumidification strategies.

Quality Control Issues

Hot market conditions sometimes lead to rushed construction with missed inspections and quality shortcuts. New home warranties help address these issues, but thorough inspection remains important even for brand-new construction.

Universal Denver Issues

Regardless of construction era, certain issues affect most Denver homes:

  • Radon: Elevated levels common across all eras; testing recommended for every purchase
  • Expansive soil: Foundation movement affects homes of all ages; severity varies
  • Hail damage: Any roof in Denver faces hail exposure; damage accumulates over time
  • Altitude effects: Lower oxygen content affects combustion equipment; proper venting essential