Designing Interiors for Delhi’s Smog Season: How Interior Designers Plan for Better Indoor Air Quality
Every winter, Delhi’s skyline becomes familiar for a different reason. The haze thickens, visibility drops, and air quality becomes a major concern for people living and working across the city. While outdoor pollution receives most of the attention, an important question remains: how well are our indoor spaces prepared for Delhi’s smog season?
For interior designers, this challenge goes beyond installing an air purifier or choosing a few indoor plants. The way a home is planned, the materials used, the placement of furniture, the ventilation system and even everyday maintenance can influence indoor air quality.
Modern interior design is no longer limited to creating visually attractive spaces. It also involves understanding how buildings respond to their environment and how design decisions affect the people using them.
In a city like Delhi, where air pollution becomes particularly challenging during autumn and winter, designing interiors with indoor air quality in mind is an important part of creating comfortable, functional and responsible living spaces.
Understanding Indoor Air Quality During Delhi’s Smog Season
Indoor air quality refers to the condition of the air inside homes, offices, educational institutions and other enclosed spaces.
Many people assume that remaining indoors automatically protects them from outdoor air pollution. However, fine particles can enter buildings through open windows, gaps around doors, poorly sealed openings and ventilation systems.
Air pollution can also originate inside the building.
Common indoor pollution sources include:
- Cooking smoke and airborne grease particles
- Dust from furniture, carpets and soft furnishings
- Paints, adhesives and certain furniture finishes
- Incense, candles and tobacco smoke
- Cleaning sprays and fragranced products
- Damp surfaces and moisture-related mould growth
Two important outdoor pollutants during Delhi’s smog season are PM2.5 and PM10. PM2.5 refers to airborne particles with a diameter of 2.5 micrometres or smaller, while PM10 includes larger inhalable particles.
These particles are important considerations because outdoor pollution can contribute to indoor exposure, even when windows remain closed.
The challenge for interior designers is therefore to create spaces that limit avoidable pollution without compromising essential ventilation, natural light, comfort or everyday functionality.
1. Begin With an Indoor Air Quality Design Brief
Before selecting furniture, colours or decorative elements, interior designers should understand the environmental conditions surrounding a property.
A ground-floor apartment beside a busy road may have different pollution challenges from a residence on a quieter upper floor. Similarly, a compact studio apartment requires different planning from a large independent house.
Study the Building’s Surroundings
The first step is to evaluate the location and immediate surroundings.
Designers should consider nearby traffic, construction activity, exposed balconies, window orientation and the frequency with which doors are opened.
They should also identify existing ventilation openings, moisture problems and areas where outdoor dust tends to accumulate.
This information helps determine which parts of the building may require greater attention.
Understand How Occupants Use Each Room
A bedroom occupied for eight hours each night has different requirements from a kitchen used for short periods throughout the day.
Questions worth discussing with clients include:
- Which rooms are occupied for the longest periods?
- Does anyone work or study from home?
- How frequently are windows and balcony doors opened?
- Are there young children or older residents?
- What cleaning and maintenance routines are practical?
Rather than applying one solution throughout the property, the designer can develop a room-specific strategy based on actual use.
2. Plan the Layout Around Cleaner-Air Zones
Space planning plays an important role in pollution-conscious interior design.
A thoughtful layout can separate pollution-generating activities from areas where people rest, work or spend extended periods.
Make Bedrooms a Priority
Bedrooms are suitable starting points for cleaner-air planning because people spend several continuous hours in them.
Design considerations may include accessible space for a correctly sized air purifier, appropriately maintained window seals, washable bedding and furniture arrangements that allow thorough cleaning.
Designers should avoid placing large cupboards or decorative panels where they obstruct airflow from filtration equipment.
A quiet, appropriately positioned air cleaner is generally more practical than a powerful unit that occupants switch off because of noise or discomfort.
Create a Practical Entrance Zone
The entrance is where outdoor dirt, footwear and frequent door opening meet the interior environment.
A compact transition area can include:
- An easy-to-clean entrance mat
- Closed shoe storage
- A designated place for outdoor clothing and bags
- Durable flooring that supports regular cleaning
These measures mainly help control dirt and dust carried indoors. They do not, by themselves, remove fine airborne particles.
In larger homes or commercial spaces, designers may also evaluate the feasibility of an entrance lobby that reduces direct airflow between the outdoors and frequently occupied rooms.
Separate Activities That Generate Pollution
Kitchens, utility areas, hobby spaces and areas used for painting or model-making may produce particles, fumes or moisture.
Where possible, the layout should reduce their direct connection to sleeping and working areas.
For compact Delhi apartments, carefully planned partitions, doors and extraction systems can help manage the movement of pollutants while preserving an open and comfortable interior.
3. Balance Ventilation With Outdoor Pollution Conditions
Ventilation is essential to maintaining indoor environmental quality, but Delhi’s winter pollution creates a design challenge.
Opening windows can introduce fresh air and help dilute pollutants generated indoors. However, during periods of severe outdoor pollution, prolonged open-window ventilation may also increase the amount of outdoor particulate matter entering a building.
This makes ventilation planning more complex than simply choosing between open and closed windows.
Reduce Uncontrolled Air Leakage
Poorly fitted windows and doors may allow polluted outdoor air and dust to enter.
Appropriate weather-stripping, door seals and window repairs can help reduce unwanted leakage.
However, an airtight room is not automatically a healthy room. Without adequate ventilation, pollutants and carbon dioxide generated indoors may accumulate.
Designers should therefore coordinate with building-service or HVAC professionals before recommending substantial changes to the building envelope.
Consider Filtered Ventilation Where Feasible
In projects with suitable building systems and budgets, mechanically supplied outdoor air can be filtered before entering occupied spaces.
The appropriate solution depends on the building, the required ventilation rate and the technical capabilities of its equipment.
Split air-conditioners commonly used in Delhi homes generally recirculate indoor air rather than provide an adequate supply of fresh outdoor air.
Understanding this distinction is essential when planning residential interiors.
Kitchens, bathrooms and spaces containing combustion appliances also require suitable exhaust and safety provisions. Necessary ventilation openings should not be blocked simply to keep outdoor pollution away.
4. Integrate Air Filtration Into the Interior Design
Air purifiers are increasingly common in urban homes, but effective air filtration requires more thought than simply choosing a compact appliance.
An interior designer should consider the room’s dimensions, furniture layout, available electrical connections, equipment noise and long-term maintenance requirements.
Understand HEPA Filtration and CADR
Many portable air cleaners use high-efficiency particulate air (HEPA) filtration to capture airborne particles.
One important specification is the Clean Air Delivery Rate, or CADR. This indicates how much filtered air a device can deliver for a particular pollutant category.
A unit suitable for a small bedroom may be insufficient for a large open-plan living and dining area.
Designers should check the manufacturer’s room-sizing guidance and relevant CADR information instead of selecting a purifier solely on appearance.
Plan Equipment Placement Carefully
An air purifier should have enough clearance around its air intake and outlet to work effectively.
Hiding a purifier inside a tightly enclosed decorative cabinet or behind heavy curtains may restrict airflow.
A better approach is to incorporate the appliance naturally into the furniture plan while following manufacturer clearance requirements.
Designers should also provide accessible power outlets and enough space to remove and replace filters.
For buildings with central HVAC systems, higher-efficiency filtration may be possible. MERV 13 filters, or the highest efficiency compatible with the equipment, are commonly recommended for particle filtration, subject to professional assessment.
Importantly, particle filters do not automatically remove gases or every indoor pollutant. Filtration should support, rather than replace, pollution source control and appropriate ventilation.
5. Choose Low-Emission Materials and Finishes
The selection of interior materials is another important consideration when planning indoor air quality.
Paints, adhesives, varnishes, sealants, engineered wood products and certain furnishings may release volatile organic compounds, commonly called VOCs.
Some emissions occur during installation, while others may continue after the project is completed.
Evaluate More Than Appearance
When comparing materials, designers should consider product-emission information alongside colour, texture, durability and cost.
Useful considerations include:
- Paints and coatings with credible low-emission testing
- Furniture and composite boards with appropriate formaldehyde-emission information
- Adhesives and sealants suitable for indoor applications
- Durable finishes that require less frequent replacement
- Products with clearly documented cleaning and maintenance requirements
Terms such as natural, green and eco-friendly should not be treated as proof of low emissions.
Include an Installation and Occupancy Plan
Material selection is only one part of responsible specification.
Newly painted walls, installed flooring, cabinets and adhesive-based finishes may require curing and ventilation according to their manufacturers’ instructions.
Designers can coordinate installation schedules so that emission-intensive work is completed before occupancy, with appropriate airing when outdoor conditions permit.
This is especially useful when major renovation work overlaps with Delhi’s winter pollution season.
6. Select Furniture and Fabrics That Are Easier to Maintain
Furniture contributes to the character of an interior, but it also influences the amount of effort required to keep the space clean.
Heavy curtains, deep-pile carpets, elaborate upholstery and open shelves filled with decorative objects can collect dust and require frequent maintenance.
This does not mean pollution-conscious interiors must look bare or clinical.
The objective is to achieve an attractive design that is also practical to maintain.
Practical Design Choices
Smooth, accessible flooring can simplify routine dust removal. Washable cushion covers, removable fabrics and well-designed closed storage can also make cleaning easier.
Furniture should be arranged so that users can reach the floor beneath beds, sofas and cabinets.
In homes where carpets or rugs are an important design feature, selecting manageable sizes and materials can help occupants maintain them consistently.
Designers should also consider how surfaces will be cleaned. A finish requiring frequent use of strong solvents or fragranced sprays may not be ideal for every indoor environment.
A carefully selected material palette can therefore combine visual warmth with sensible maintenance requirements.
7. Design Kitchens and Bathrooms With Pollution Control in Mind
Not all indoor pollution comes from outside.
Cooking, moisture and everyday household activities can affect air quality significantly, making kitchens and bathrooms important parts of an indoor air quality plan.
Kitchen Design
High-temperature cooking, frying and grilling can release airborne particles.
A properly designed and ducted kitchen exhaust hood can help capture cooking emissions near their source.
Designers should consider the relationship between the hob, hood, surrounding cabinetry and available exhaust route.
A recirculating kitchen hood is not equivalent to a system that exhausts captured pollutants outdoors.
The kitchen also needs easily accessible surfaces for cleaning accumulated grease and dust.
Bathroom and Utility Design
Persistent moisture may encourage mould growth and damage interior finishes.
Suitable exhaust, waterproofing, drainage and the prompt repair of leaks should be considered during the design process.
Decorative wall treatments should never be used to conceal an unresolved dampness problem.
In both kitchens and bathrooms, ventilation must be planned with appropriate make-up air and building safety requirements in mind, particularly during periods when outdoor air pollution is severe.
8. Use Biophilic Design Without Relying on Plants for Air Purification
Indoor plants, natural textures and daylight can make interiors feel more inviting and connected to nature.
These elements are part of biophilic design, an approach that brings natural experiences and environmental qualities into built spaces.
However, indoor plants are often promoted as a simple solution for air purification.
Research does not support the idea that a few decorative houseplants can meaningfully replace mechanical filtration or ventilation in an ordinary occupied room.
Plants should instead be selected for their appearance, lighting requirements and maintenance needs.
Designers can explore biophilic features through natural materials, views of greenery, carefully controlled daylight and nature-inspired patterns.
Readers interested in this broader approach can explore LSOD’s article on biophilic interior design trends.
In Delhi, the most thoughtful interiors combine these calming elements with practical pollution-management measures rather than relying on greenery alone.
9. Use Air Quality Monitoring to Inform Design Decisions
Monitoring provides a way to observe how an interior performs after it is occupied.
Compact indoor air quality monitors can help occupants identify changes in particulate matter, temperature, humidity and, depending on the device, other environmental conditions.
For example, a PM2.5 monitor may reveal a rise in particle levels during cooking or after a balcony door has remained open.
A carbon dioxide monitor may help indicate changes in occupancy and ventilation conditions, although CO2 readings do not measure particulate pollution directly.
Low-cost air sensors can have accuracy limitations, so readings are often most useful for observing patterns rather than establishing a definitive health or safety assessment.
Interior designers can incorporate monitoring locations into the plan without making the devices unnecessarily prominent.
Sensors should be positioned according to manufacturer guidance and away from locations where direct airflow, heat or nearby pollution sources could distort readings.
10. Prepare Interiors for Seasonal Changes
Delhi’s environmental conditions are not identical throughout the year.
The city can experience severe particulate pollution during autumn and winter, while warmer months bring different concerns involving heat, dust and ventilation.
A flexible interior design should support adjustments rather than depend on a single operating condition.
For example, during periods of poor outdoor air quality, occupants may prioritise keeping windows closed where appropriate while operating suitable air filtration and maintaining necessary safe ventilation.
When outdoor conditions improve, appropriate ventilation can help reduce pollutants generated indoors.
Designers can prepare a simple operating guide explaining how to use windows, exhaust systems, air cleaners and other building equipment under different conditions.
Maintenance is equally important.
Filters eventually require cleaning or replacement. Window seals may deteriorate, exhaust systems need servicing, and moisture problems may emerge over time.
Planning for these requirements can help preserve the practical value of the design.
11. How Interior Designers Can Apply These Principles in a Delhi Apartment
Consider a hypothetical two-bedroom apartment in South Delhi located near a busy road.
The residents want a modern interior with an open living area, comfortable bedrooms and a home workspace.
An interior designer could approach the project in stages.
Stage 1: Site assessment
The designer documents road-facing openings, window conditions, existing ventilation and the spaces used most frequently.
Stage 2: Space planning
Sleeping and working areas receive priority. The layout incorporates practical shoe storage, accessible cleaning routes and separation between the cooking area and quieter spaces.
Stage 3: Material selection
The design specification includes emission information for paints, boards, adhesives and major furnishings, alongside durability and maintenance criteria.
Stage 4: Equipment coordination
The designer reserves suitable locations and power outlets for room air cleaners and consults appropriate specialists about kitchen exhaust and ventilation.
Stage 5: Project handover
The completed project includes guidance for cleaning, ventilation, equipment operation and filter replacement.
The result is not a guarantee of pollution-free indoor air. It is a more considered design that addresses real environmental constraints alongside appearance, comfort and everyday use.
This example demonstrates how indoor air quality becomes part of the design process instead of an accessory added at the end.
12. What Aspiring Interior Designers Can Learn From This Challenge
Delhi’s smog season presents an important learning opportunity for students interested in the future of interior design.
Designers increasingly need to understand the relationship between interior spaces, building services, materials and environmental performance.
A student project focused on indoor air quality could involve preparing a site analysis, developing a room-zoning plan, comparing material specifications and coordinating equipment locations.
Students could also explore how budget limitations influence design decisions.
For example, when a client cannot install a sophisticated ventilation system, the designer still has opportunities to improve space organisation, material choices, maintenance access and the placement of appropriately sized portable filtration equipment.
These projects encourage critical thinking and help students recognise that good interior design involves problem-solving as much as visual creativity.
At Leher School of Design’s Diploma in Interior Design, students can explore areas such as space planning, building materials, drafting and building services. These foundational subjects are relevant to understanding how interior design decisions interact with the built environment.
As environmental challenges influence the expectations placed on buildings, the ability to combine creative thinking with practical technical knowledge becomes increasingly valuable.
Conclusion
Designing interiors for Delhi’s smog season requires more than choosing an air purifier or creating a visually clean space. It calls for an understanding of how air moves through buildings, how materials contribute to indoor conditions and how people use their environments every day.
From room zoning and ventilation coordination to low-emission finishes, manageable furniture layouts and long-term maintenance, interior designers can make informed choices that support better indoor air quality.
The most successful approach combines aesthetics, functionality and environmental awareness without promising completely pollution-free interiors.
For aspiring designers, this challenge highlights an important direction in the profession. Interior design is not only about how a space looks, but also how thoughtfully it responds to its surroundings and supports the people who live and work within it.